A taxonomic revision of Acanthaceae tribe Barlerieae in Angola and Namibia. Part 2

The second part of a taxonomic revision of the tribe Barlerieae (Acanthaceae) in Angola and Namibia covers Barleria sects. Somalia and Stellatohirta. Thirty-one taxa including 27 accepted species are treated. Four new species (Barleria eburnea, B. imatensis, B. louiseana and B. thunbergiiflora), one new subspecies (B. kacondensis subsp. glabrescens) and one new variety (B. violascens var. humpatana) are described. In addition, B. taitensis S.Moore var. occidentalis S.Moore is elevated to subspecies status and B. newtonii Lindau is resurrected as a distinct species endemic to the Lubango Highlands of Angola. Full descriptions, citations of types and representative specimens, and notes on their habitat(s), ecology and biogeography are provided for each taxon. Thirteen names in Barleria are lectotypified and a neotype is selected for B. newtonii. A preliminary assessment of the conservation status and extinction risk is provided for each taxon. Of the 31 taxa enumerated, five are assessed as Endangered, two as Vulnerable, two as Near Threatened, and 13 are of Least Concern, whilst nine are currently considered to be Data Deficient. This contribution completes our revision of Barleria in Angola and Namibia, with 59 accepted species, four additional subspecies, four additional varieties and two incompletely known taxa documented in total. A remarkable 75% of the taxa are endemic or near-endemic to Angola and Namibia.


Introduction
This paper presents the second and final part of the revision of Barleria L. (Acanthaceae: Acanthoideae: Barlerieae) in Angola and Namibia, continuing on from Part I of this work (Darbyshire et al. 2019a), which treated subg. Barleria and subg. Prionitis (Nees) C. B.Clarke sect. Prionitis Nees. Here, we complete the revision of species in subg. Prionitis, as redefined by Darbyshire et al. (2019b), by treating sects. Somalia (Oliv.) Lindau and Stellatohirta M. Balkwill (Table 1). For a detailed background to this study and its objectives, the reader should refer to the Introduction in Darbyshire et al. (2019a). Sects. Somalia and Stellatohirta are challenging in the study region because many of the taxa are restricted to Angola alone and are known from very few collections (see Introduction in Darbyshire et al. 2019a for more discussion on this point), hence infraspecific variation can be difficult to assess and species delimitation is sometimes problematic. Furthermore, the paucity of collections for many taxa causes difficulties with assessment of their conservation status and extinction risk. However, given the fact that large areas of Angola are experiencing rapid habitat declines and transformation as a function of human population density and so the threats to plant species are often extreme (Mendelsohn 2019), we have tried to apply a provisional assessment for the species in question using the categories and criteria of the IUCN Red List (IUCN 2012; IUCN Standards and Petitions Committee 2019) avoiding wherever possible the Data Deficient category. However, we acknowledge that for many species, further data on range and population sizes are highly desirable.
In the discussion section, we present an overview of the distributional patterns and species richness of Barleria across Angola and Namibia, placed in the context of wider phytogeographical patterns in the region.

Materials & Methods
The materials and methods used in this study were described in Darbyshire et al. (2019a). The numerical sequence of the species continues from that work, in which 32 species were documented. As there has been past confusion over the circumscription of Barleria alata S. Moore and B. elliptica Benoist, we cite all material seen for these species, including collections from outside the study region, although we only map the Angolan portion of their ranges. For all other species, specimen citations are restricted to the study region. For species where there is considerable variation outside of the study region, most notably in B. matopensis S. Moore and B. taitensis S.Moore, we include notes on and keys to the variation across their respective ranges.
Since the publication of Darbyshire et al. (2019a), a major, multi-author volume on the biodiversity of Angola has been published (Huntley et al. 2019a), which provides useful information relevant to the current study. In particular, the chapters on the flora of Angola (Goyder & Gonçalves 2019) and landscape changes in Angola (Mendelsohn 2019) have informed the current work.
Some recent collections by D. J. Goyder (K) from Angola are housed in the fledgling herbarium of the government's Instituto Nacional da Biodiversidade e Áreas de Conservação, which is not yet listed on Index Herbariorum; this is abbreviated to 'INBAC' (following Darbyshire & Goyder 2019).
The species distribution maps were produced using QGIS version 2. 14.4, whilst the species richness maps were produced in QGIS version 3.10 (available online a t h t t p s : / / w w w . q g i s . o r g / e n / s i t e / f o r u s e r s / download.html). Species richness is mapped using a grid with each square measuring half a degree of latitude and longitude.

Taxonomic Account continued
To assist with understanding of the descriptions and keys, the reader should refer to the notes on terminology, presented in Darbyshire et al. (2019a: 6). The key to infrageneric taxa in Barleria can be found in Darbyshire et al. (2019a: 7).
Barleria subg. Barleria (addendum) Since the publication of the first part of this revision, photographs have become available of two of the species of subgen. Barleria that were not previously illustrated by colour images: B. elegans S.Moore ex C. B.Clarke subsp. elegans and B. crabbeoides I. Darbysh., and better photographs have become available for B. rupicola I. Darbysh. These are included here in Fig. 1. As B. crabbeoides is a rare species that was newly described in Darbyshire et al. (2019a), we include the details of the additional collection below. 21. Barleria crabbeoides I. Darbysh. (in Darbyshire et al. record); https://www.inaturalist.org/observations/ 33554726; https://www.inaturalist.org/observations/ 33554727. NOTES. With the additional information provided from the above field observation, a full conservation assessment of this species has been possible and it has been assessed as Endangered -EN B1ab(iii)+2ab(iii) (Darbyshire et al. 2020b).

mm.
Capsule not seen. DISTRIBUTION. Endemic to Southwest Angola (Huíla and Namibe Provs.); Map 1. ADDITIONAL COLLECTIONS STUDIED. ANGOLA. Moçâmedes, Humbia -Chela Hills, fl. 20 May 1937, Gossweiler 10962 (BM!, K!, P*); a 40 km de Sá da Bandeira [Lubango] na estrada para Vila Arriaga [Bibala], fl. 7 June 1962, Figueira de Sousa 222 (LUBA!). HABITAT & ECOLOGY. Gossweiler recorded this species from dry forest ("hiemisilva"); no other habitat data are available; it occurs at c. 950 -1900 m elevation. It has so far been recorded only from the Lubango Highlands of the Huíla Plateau. CONSERVATION STATUS. Based on current evidence, this species is endemic to the Lubango Highlands where it is apparently scarce, as it has only rarely been collected despite its large, showy corollas and despite this area being well botanised relative to other parts of Angola. This area has been subject to extensive natural habitat loss and intact vegetation is now largely restricted to steeper slopes and gullies. The main drivers of habitat loss in Huíla (as elsewhere in Angola) are agricultural activities, increased frequency of fire, fuelwood extraction, charcoal production and urban development (Chisingui et al. 2018). With an extent of occurrence (EOO) of c. 200 km 2 , fewer than five locations known and an ongoing decline in extent and quality of habitat, this species is considered to be Endangered -EN B1ab(iii). NOTES. Although the original type material of Barleria newtonii is believed to have been destroyed, the extant specimens cited clearly match the description in the protologue. The neotype selected here was collected from close to the original type locality and is excellent flowering material.
Barleria newtonii is here resurrected as a good species. Clarke (1899) considered it to be conspecific with B. calophylla Lindau, today known from South Sudan and the Central African Republic. The two species do look quite similar on a superficial level but there are numerous differences. Barleria calophylla has (1) a pale pink or rose-pink corolla lacking any spots on the lobes, with a much less strongly offset abaxial lobe and with short glandular hairs externally at least on the lateral lobes, the tube often also with coarser eglandular hairs; (2) considerably longer bracteoles that vary from being subulate to elliptic and leafy; (3) outer calyx lobes with a rounded, not cordate, base, and (4) the leaves and bracts typically dry blackish-green whereas in B. newtonii they dry green. There is no doubt that they are separate species. Barleria calophylla is noted to have 4-seeded capsules (I. D., pers. obs.); the capsules of B. newtonii are not known but based on similarity to the following group of species (spp. 34 -39) they are considered likely to be 2-seeded. 34. Barleria imatensis I. Darbysh. sp. nov Barleria polyneura sensu Brummitt & Seyani (1978: 726), pro parte, non S.Moore (1880: 266).

A D D I T I O N A L C O L L E C T I O N S S T U D I E D . A N G O L A .
Tchivinguiro, próximo da Escola de Regentes Agrícolas, fl. 5 Jan. 1962 Barleria imatensis is recorded from secondary dry "forest" (more likely to be a form of xeric woodland) on limestone outcrops and in dry places with Bauhinia sp.; it occurs at c. 1200 -1550 m elevation. CONSERVATION STATUS. This species is known only from two historic locations in southwest Angola. Satellite imagery available on Google Earth shows that at both of these sites there are areas of land extensively transformed due to agricultural activity. However, in the vicinity of the Instituto Médio Agrario do Tchivinguiro there are still areas of intact natural vegetation where this species may well be found. Further, the Cunene part of its range is underexplored botanically, and areas away from the main transport routes appear to have some intact vegetation still in place. This species may also be protected from some of the most severe human impacts by its preference for rock outcrops, although this requires confirmation. With more information needed on the full range, abundance and threats to this species, it is currently assessed as Data Deficient -DD, but it may well prove to be threatened once more complete data are available. ETYMOLOGY. This species is named after the Instituto Médio Agrario do Tchivinguiro (IMAT, formerly the Escola de Regentes Agrícolas do Tchivinguiro), the type locality for this species. It is hoped that this species can be rediscovered and protected within the grounds of this Institute. NOTES. This species has previously been included within Barleria polyneura (Brummitt & Seyani 1978;Darbyshire 2010) but, although they are clearly closely allied, they differ in quite a number of characters as listed in the Recognition section. More material is desirable to confirm some of the differences e.g. in corolla form, but we have little doubt that they are different species.  B. benguellensis and B. violascens together form a species complex and they could ultimately prove to be variants of a single species, or perhaps two species with B. polyneura maintained as separate from B. violascens (including B. benguellensis). They all share the combination of trailing, procumbent or weak decumbent branches, red-brown stems, largely glabrous foliage and broad, ovate or ovate-elliptic, largely glabrous calyces. However, based on the material seem to date, they are easily separated vegetatively and so are maintained as distinct here, with two varieties recognised within B. violascens. 35. Barleria polyneura S.Moore (1880: 266); Clarke (1899: 157); Hiern (1900: 815); Moore (1930: 134); Brummitt & Seyani (1978: 726), pro partesee note; Klopper et al. (2006: 4); Makholela (2008: 22 Suffruticose herb, several branched from a woody rootstock, stems prostrate, procumbent or weakly Map 1. Distribution of Barleria newtonii (red triangles), B. pabularis (black circles), B. welwitschii (yellow diamond) and B. louiseana (blue squares). ascending, 10 -30 cm long, drying dark red-brown, with pale antrorse or spreading hairs sparse and restricted to two opposite lines, later glabrescent. Leaf buds densely pubescent with cream-coloured hairs but soon glabrescent. Leaves subsessile, blade somewhat coriaceous, glaucous-green but often drying browngreen, largest leaves ovate, 4.3 -7 × 2.6 -3.7 cm (l:w ratio 1.3 -2.1: 1), base rounded, subcordate or obtuse, margin entire, apex acute-or obtuse-apiculate, surfaces glabrous; lateral veins 4 -7 pairs, these and reticulate tertiary venation prominent beneath. Inflorescences of single-flowered cymes in upper axils; bracts foliaceous but those towards stem apices reduced, often elliptic or obovate with base attenuate, typically 16 -37 × 7.5 -21 mm; cymes subsessile or peduncles to 6 mm long; bracteoles erect or ascending, either linear or oblanceolate, 4 -22 × 0.5 -9 mm, ± conduplicate, apex acute or rounded, surfaces glabrous; pedicels 2.5 -7 mm long, appressed-pubescent or glabrous. Calyx often drying dark green or purplishbrown, somewhat accrescent; anterior lobe broadly ovate, 18.5 -25.5 × 13.5 -19 mm in flower, up to 28 × 21.5 mm in young fruit, base cordate, margin entire, apex shallowly notched or emarginate for up to 1 mm, surface glabrous, palmate venation prominent; posterior lobe as anterior lobe but 19 -28.5 mm long in flower, up to 32 mm long in fruit, apex obtuse or acute; lateral lobes linear-lanceolate, 9 -14 mm long, often curved outwards, glabrous. Corolla 35 -43 mm long, white or cream, sometimes with violet throat, glabrous externally; tube 13.5 -18.5 mm long, cylindrical below attachment point of stamens where 3 -3.5 mm in diam., narrowly funnel-shaped above, mouth 5 -5.5 mm in diam.; limb subregular, abaxial lobe slightly offset from remaining lobes, obovate-elliptic or -orbicular, 17.5 -21.5 × 13 -15.5 mm, apex rounded or slightly emarginate; lateral lobes obovate or elliptic, 20.5 -21.5 × 13 -14.5 mm; adaxial lobes as lateral lobes but 17 -21 × 9.5 -11.5 mm. Stamens inserted c. 5 mm from base of corolla tube; filaments 10.5 -14.5 mm long; anthers 3.4 -3.8 Lubango and Quipungo in Huíla Province, has been particularly heavily impacted by human activities (Mendelsohn 2019), including agricultural expansion, increased frequency of fire, fuelwood extraction, charcoal production and urban development (see Chisingui et al. 2018). This species' apparent preference for rocky areas may protect it from some of these pressures but this requires confirmation. Although not known to occur in any protected areas, the southwestern-most site at Cuvelai is close to the Mupa National Park, and the northern portion of the Bicuar National Park also lies within this species' EOO. If found there, these extensive protected areas may offer some protection for this species. Recent studies of woody plant and habitat diversity and structure in Bicuar National Park have noted that this extensive site is still relatively well preserved with extensive intact dry miombo woodland assemblages, despite significant past pressures including selective logging of species and farming activity (da Silva et al. 2020;Godlee et al. 2020). That said, the reserve was reduced from 7,900 km 2 to 6,754 km 2 due to conversion of natural habitat to commercial and subsistence agricultural land in the west and north (Mendelsohn & Mendelsohn 2018) and there are some ongoing pressures on the park's habitats that need to be better understood and managed (da Silva et al. 2020). The national parks of Angola in general remain highly under-resourced, often without effective management and some, including Mupa, are threatened (Mendelsohn & Mendelsohn 2018;Huntley et al. 2019b). Based on current evidence, this species is assessed as Near Threatened -NT B1ab(iii) as fewer than 10 locations are known and there are clear threats, but the EOO falls just outside the threshold for Vulnerable under criterion B1. NOTES. Barleria polyneura is easily separated from B. benguellensis and B. violascens by the broadly ovate mature leaves with rounded, obtuse or subcordate bases (cuneate or attenuate in the other two species) and by the broader calyces with a more markedly cordate base, the apex of the posterior lobe usually being obtuse. Brummitt & Seyani (1978) assigned several collections of a Barleria species from Malawi to B. polyneura, stating that the only difference between the highly disjunct populations was the cuneate leaf base in the Malawi material, this being rounded in Angolan specimens. The Malawi plants have since been reidentified as B. calophylloides Lindau subsp. pilosa I. Darbysh. (Darbyshire 2010: 396;2015: 97), with several notable differences to B. polyneura, particularly the much larger corolla 50 -60 mm long with tube 25 -33 mm long. This close relationship to B. calophylloides sensu stricto, from Tanzania and Zambia, has recently been confirmed by RADseq phylogenetic analyses (Comito 2019). Barleria polyneura has not yet been sequenced but the closely allied B. violascens is placed as sister to B. calophylloides with strong support. S.Moore (1911: 305); Moore (1930: 135);Klopper et al. (2006: 3); Makholela (2008: 21 Suffruticose herb, many-branched from a perennial rootstock (not seen), stems trailing or decumbent, to 30 -40 cm long, drying dark red-brown, with two opposite lines of pale ± antrorse or spreading hairs, later glabrescent. Leaves subsessile, blade somewhat coriaceous, glaucous-green but can dry brown-green, ovate or ovate-elliptic when mature, 6.5 -8.7 × 2.2 -3.5 cm (l:w ratio 2.1 -3: 1), base cuneate or attenuate, margin entire, apex acute, apiculate, surfaces glabrous or with few strigulose hairs along margin towards leaf base; lateral veins 7 -8 pairs, these and reticulate tertiary venation ± prominent beneath; young leaves narrowly oblong-elliptic and with apex sometimes more rounded. Inflorescences of singleflowered cymes aggregated into congested terminal spikes 4.5 -6 cm long and also with solitary flowers in uppermost leaf axils; bracts in the spike foliaceous but much reduced, ovate-elliptic, 20 -29 × 5 -11 mm, can be pale yellowish-green in dry state; cymes subsessile or peduncle to 3 mm long; bracteoles held erect or ± ascending, linearlanceolate or -oblanceolate, 5 -18 × 0.7 -3 mm, conduplicate, margin pale-strigulose or glabrous, entire or with minute teeth formed by swollen hair bases; pedicels 2 -4 mm long, pale-strigulose. Calyx yellowish-green or brown in dry state; anterior lobe ovate, 17.5 -27 × 14 -18 mm, base rounded or subcordate, margin entire, apex notched with two triangular lobes 1 -3.5 mm long, surfaces glabrous except for pale-strigulose margin, with ± prominent palmate venation; posterior lobe as anterior lobe but 22 -31 mm long, apex acute or somewhat attenuate and apiculate, margin often involute, midrib sometimes with few multicellular crisped hairs towards base; lateral lobes lanceolate-attenuate, [12][13]  now heavily transformed by human activities including agriculture and settlement, as evidenced from Google Earth imagery. However, with only limited habitat information available and with some uncertainty over the taxonomy of this species (see Notes), it must currently be assessed as Data Deficient -DD. NOTES. This species is most likely to be confused with Barleria violascens, the main differences being that B. benguellensis has considerably larger and broader leaves with l:w ratio 2.1 -3: 1 (vs 3 -10.5: 1), and a more contracted compound inflorescence. In addition, the type specimen has a more markedly funnelshaped corolla tube, c. 9 -10 mm diam. at the mouth (vs campanulate to narrowly funnel-shaped, 3.5 -7 mm diam. at the mouth in B. violascens) and larger anthers (4.7 -5.2 mm long, vs 3 -4 mm long). However, a second collection that closely matches the type specimen vegetatively (Menezes et al. 4618) has smaller, less markedly funnel-shaped corollas with shorter, broader lobes and with smaller stamens, all of which are similar to B. violascensthe floral measurements for this second collection are placed in square brackets in the description here. The type locality is quite distant from the locality of this second collection and it is possible that they represent different taxa that are vegetatively similar. Barleria violascens S.Moore (1880: 265); Hiern (1900: 815); Moore (1930: 135);Klopper et al. (2006: 5); Makholela (2008: 22   Suffruticose herb, fewmany branched from a woody rootstock, stems prostrate or procumbent, 5 -30 cm long, usually drying dark red-brown, with pale ± antrorse hairs restricted to or most dense on two opposite sides. Leaf buds often densely pubescent with cream-coloured hairs. Leaves sessile or petiole to 7 mm long; blade somewhat coriaceous, glaucous-green but often drying green-brown, narrowly elliptic, lanceolate or linear-lanceolate, 2.8 -8.6 × 0.4 -2 cm (l:w ratio 3 -10.5: 1), base cuneate or attenuate, margin entire or shallowly undulate, apex acute-apiculate, surfaces glabrous or midrib strigulose beneath, young leaves sometimes with dense fine whitewooly hairs but these ± soon caducous; lateral veins 5 -7 pairs. Inflorescences of single-flowered cymes in upper axils, sometimes aggregated into loose leafy terminal spikes to 6 cm long; bracts foliaceous but those towards the stem apices much reduced, then typically oblong-elliptic to subulate, 23 -56 × 3 -10 mm; cymes subsessile or peduncles to 6 (-11.5) mm long; bracteoles ascending or spreading, narrowly oblanceolate or subulate, 7 -30 × 1 -4.5 mm, often conduplicate, glabrous or margin and midrib with few pale antrorse hairs, midrib sometimes also with spreading multicellular hairs; pedicels absent or to 4.5 mm long, appressed-pubescent. Calyx green with purplish veins or purple throughout, often drying brown, accrescent; anterior lobe ovate or ovate-elliptic, 15.5 -23.5 × 10 -17 mm in flower, up to 32.5 × 21 mm in fruit, base rounded or shallowly cordate, margin entire, often involute, apex shallowly notched to more deeply bifid for 0.3 -6 mm, surfaces glabrous or margin and lower portion of midrib with pale antrorse or appressed hairs, rarely midrib with few spreading multicellular hairs; posterior lobe as anterior lobe but 17 -27 mm long in flower, up to 36.5 × 24 mm in fruit, apex acute or attenuate and apiculate; lateral lobes linear-lanceolate, 7 -9 mm long, with sessile glands on surface. Corolla 32 -53 mm long, purple, blue-purple or lilac throughout or with lobes or whole flower white, glabrous externally; tube 16 -25.5 mm long, cylindrical below insertion point of stamens where 2.5 -4 mm in diam., narrowly campanulate above, mouth 3.5 -7 mm diam.; limb subregular, abaxial lobe obovateorbicular to oblong-obovate or -elliptic, 15 -23.5 × 7 -16.5 mm, apex rounded or emarginate; lateral lobes obovate to oblong-elliptic, 15 -25.5 × 6 -15 mm, apices obtuse to rounded; adaxial lobes as lateral lobes but 14.5 -23 × 4.5 -12.5 mm. Stamens inserted 5.5 -6.5 mm from base of corolla tube; filaments 11.5 -16 mm long; anthers 3 -4 mm long, held at corolla mouth; lateral staminodes sometimes barely developed, 0.5 -2.5 mm long. Pistil glabrous; stigma linear, 1.9 -2.7 mm long, curved. Capsule 2-seeded, 17.5 -23 mm long including beak 6.5 -9 mm long, glabrous; seeds 8.3 -9.5 × 7.2 -7.6 mm. Fig. 3C & D. 37a. Barleria violascens S.Moore var. violascens Leaves narrowly elliptic or lanceolate, 8 -20 mm wide, l:w ratio 3 -4.7: 1. Fig. 3C. DISTRIBUTION. Endemic to Southwest Angola (Cunene, Cuando Cubango, Huíla and Namibe Provs.); Map 3. ADDITIONAL COLLECTIONS STUDIED. ANGOLA Var. violascens is recorded from open and degraded woodland, Julbernardia ("mumua") woodland and thicket including on shallow soils in areas of exposed laterite, and open areas with rocky outcrops; it occurs at c. 1150 -1750 m elevation. CONSERVATION STATUS. This subspecies is restricted to southern Angola, with an EOO of 40,211 km 2 based on known occurrence data. This is well in excess of the upper limit for a threatened category under IUCN Criterion B1. The western and northern parts of its range have a high human population and extensive losses of natural vegetation cover due to settlement, agriculture and firewood extraction, and this loss is ongoing (see Mendelsohn 2019, figs. 8.1 and 8.8). However, this subspecies appears to be tolerant of some disturbance, and occupies a variety of habitats including areas that are likely to be protected from the most severe human disturbance, such as rock outcrops. Therefore, although the population may well be in decline, it is provisionally assessed as of Least Concern -LC. NOTES. Spencer Moore wrote on the BM sheet of Gossweiler 3124 and 3813 "this is a new species but not described in the absence of a satisfactory corolla. It comes close to B. polyneura and B. violascens, having much the outer calyx segments of the former and leaves of the latter species". However, it is our view that these two specimens (and also Gouveia 1173 which is a close match) are fruiting material of Barleria violascens; the calyx is accrescent which accounts for the difference to the flowering material previously seen by Moore, but it still has the acute or attenuate apices to the calyx lobes and the slender leaves and long slender bracteoles clearly match B. violascens. 37b. Barleria violascens S.Moore var. humpatana I. Darbysh. var. nov. Type: Angola, Humpata, prox. do campo da Aviação, fl. 30 Jan. 1956, Torre 8560 (holotype LUBA!).

37.
http://www.ipni.org/urn:lsid:ipni.org:names:77215730-1 Leaves linear-lanceolate or very narrowly oblong, 4 -9 mm wide, l:w ratio (4.7 -) 6 -10.5: 1. Fig. 3D. RECOGNITION. Var. humpatana is separated from var. violascens by its narrower, linear-lanceolate or very narrowly oblong leaves which are typically over six times longer than wide (vs leaves narrowly elliptic or lanceolate, typically less than five times longer than wide). DISTRIBUTION. Endemic to the Lubango Highlands in Southwest Angola (Huíla Prov.); Map 3. ADDITIONAL COLLECTIONS STUDIED. ANGOLA. Humpata, na margem do Rio Nene, fl. 14 Feb. 1957, Teixeira 2029 (LUBA!, PRE!); Humpata, Estação Agricola da Humpata, fl. 20 Feb. 1957 CONSERVATION STATUS. This variety is restricted to the area around and northwest of Humpata in the Lubango highlands, with an EOO of only 162 km 2 . It was recorded as frequent and abundant by Teixeira (2087) but was found to be uncommon during recent botanical exploration in this area (Crawford FC 373). Much of the natural vegetation of the Humpata area has been transformed by human settlement and intensive agricultural activities. This variety can occur in rocky habitats that are likely to have been spared from the most intense human activities in these highlands, and it is tolerant of some disturbance and can persist in secondary vegetation. Even so, it is highly likely to have experienced population declines due to habitat transformation. With fewer than five locations known, it is therefore assessed as Endangered -EN B1ab(iii)+2ab(iii). NOTES. This variety is restricted to the Humpata area south to Jau in the western Lubango highlands; var. violascens is usually recorded from lower altitudes, chiefly in the Cubango and Cunene catchments but also occurs in the eastern Lubango highlands and the two may not be entirely allopatric in the Lubango region. Santos & Henriques 379 from the Miradouro da Tunda Vala, fl. 10 Dec. 1961 (LUBA!) is intermediate between the two varieties. Given that the Humpata taxon is separated only on leaf shape, although this gives it a strikingly different appearance to most specimens of B. violascens, it is here treated at the varietal rank. In some specimens of var. humpatana (most notably Crawford FC373), the young leaves have a fine wooly indumentum which is later glabrescent; however, in other material these hairs are more quickly caducous. This character has not been seen in var. violascens although the leaf buds there are densely hairy. Herb, basal parts not seen, stems red-brown at least when young, glabrous except for minute hairs on two opposite sides when young. Leaves sessile or petiole to 5 mm long; blade drying brown, narrowly lanceolate, 5.2 -7.3 × 0.8 -1 cm (l:w ratio 6 -8: 1), base cuneate, margin entire, somewhat revolute, apex acute-apiculate, surfaces glabrous; lateral veins 4 -5 pairs but obscure, midrib prominent beneath. Inflorescences of single-flowered cymes aggregated into a terminal spike 4.5 -5.5 cm long, sometimes with additional singleflowered cymes in upper leaf axils; bracts foliaceous but rapidly reducing up the spike where narrowly oblong-elliptic or -lanceolate, 27 -34 × 7 -9 mm, can be caducous in fruit; peduncle of each cyme to 2.5 mm long in fruit or those of lowermost cymes up to 10.5 mm long, glabrous; bracteoles ascending, narrowly oblong-elliptic or somewhat oblanceolate, 15 -26 × 3 -5.2 mm, conduplicate, glabrous. Calyx ?purplish; anterior and posterior lobes subequal, elliptic-rhombic, 21 -24 × 9 -10 mm in fruit, base cuneate or attenuate, margin involute, apex of anterior lobe notched for c. 1 mm with acute-triangular lobes, posterior lobe acute, surfaces glabrous; lateral lobes linear-lanceolate, 8.5 -10 mm long in fruit, glabrous. Corolla not seen. Capsule 2-seeded but with vestigial remains of second seed per locule apparent at slightly tapered base, 23 -24 mm long including beak 6.5 mm long, glabrous; seeds c. 9.5 × 8 mm. DISTRIBUTION. Southwest Angola (Huíla Prov.); Map 3. No habitat information is recorded on the single known specimen. CONSERVATION STATUS. In view of the uncertain taxonomic status of this taxon and the lack of habitat information, it is assessed as Data Deficient -DD. NOTES. The single specimen seen lacks basal parts and flowers. From the fruiting material, it appears to be close to the Barleria polyneura-violascens group, sharing the largely glabrous vegetative parts and calyces, reddish-brown stems and glabrous, 2-seeded capsules. It looks most similar to B. violascens, sharing the narrowly lanceolate leaves of that species, and could be a variant of that species but it differs in having elliptic-rhombic outer calyx lobes with a cuneate or attenuate base (vs ovate to ovate-rhombic with a rounded or shallowly cordate base in B. violascens), and a more well-defined and dense terminal inflorescence.
The M and WAG sheets are believed to be derived from the same collection but the label data differ slightly on the two sheets; the WAG sheet has the extra locality "Tschiwinguru" recorded, and the date is given only as "1954/55". Suffruticose herb, branched from a woody base, with a woody tuberous rootstock, stems erect, 10 -30 cm tall, tinged purple when young, pubescent with pale ± antrorse hairs, most dense on two opposite sides. Leaves sessile or petiole to 2 mm long; blade glaucousgreen, narrowly oblong-lanceolate, 5.5 -7 × 0.6 -1.2 cm (l:w ratio 5 -8.5: 1), base cuneate, margin entire, apex acute-apiculate, margin antrorse-pubescent, midrib with longer antrorse or more spreading hairs beneath; lateral veins 5 -7 pairs but obscure.
Inflorescences of few single-flowered cymes crowded in the upper leaf axils; bracts foliaceous but those towards the stem apices somewhat reduced, 25 -44 × 3.5 -6.5 mm; flowers subsessile; bracteoles ascending, subulate or narrowly oblanceolate, 12 -21 × 1.5 -2.2 mm, conduplicate, antrorse-pubescent. Calyx pale green-brown; anterior lobe ovate-rhombic, 18 -24 × 11 -12 mm, base obtuse, margin involute, apex notched for 1.2 -3 mm, external surface densely pale antrorse-pubescent; posterior lobe as anterior lobe but somewhat longer, apex ± attenuate and apiculate; lateral lobes straw-coloured, lanceolate-attenuate, 8.5 -9.5 mm long, pubescent. Corolla [measurements based on one flower] c. 35 mm long, white, glabrous externally; tube 15.5 mm long, cylindrical below insertion point of stamens where 3.5 mm in diam., narrowly widened above, mouth 6.5 mm in diam.; limb subregular, abaxial lobe obovate-orbicular, 17.5 × 15 mm; lateral lobes obovate, 15 × 12 -14 mm; adaxial lobes obovate, 16 × 11.5 mm. Stamens inserted 5 mm from base of corolla tube; filaments 12 -13 mm long; anthers 3.7 -4.3  HABITAT & ECOLOGY. The single specimen seen was recorded from on clay soils at c. 1700 m elevation; no further habitat information is available. It appears to be endemic to the Huíla Plateau. CONSERVATION STATUS. This species is recorded only from the Huíla area and the exact collecting locality of the extant specimen has not been confirmed. It is clearly scarce, as this part of Angola has been more thoroughly botanised than most parts of Angola. The Huíla Highlands have been heavily denuded of their vegetation with extensive conversion to farmlands and this is likely to have impacted this scarce species. Therefore, it is highly likely to be threatened. However, with almost no habitat information available for this species, it must currently be considered Data Deficient -DD. NOTES. We have not been able to trace any duplicates of the Antunes type specimen, nor have we traced Capello 19 which is cited under this species by Clarke (1899). The description above is based solely on Teixeira 1813. This specimen broadly agrees with the description of Barleria antunesii in the protologue although there are some differences: Lindau (1895a) recorded the anterior calyx lobe as 25 × 20 mm (although Clarke 1899 says nearly 1 × 3/5 in. [= 25 × 15 mm]) and the posterior lobe as 30 × 21 mm, and he records the corolla as larger, with tube 20 mm long and lobes 25 mm long, the abaxial lobe 20 mm wide, lateral lobes 15 mm wide and adaxial lobes 13 mm wide. The larger calyces could potentially be accounted for by accrescence at maturity and the variation in corolla size is not unusual in Barleria. Clarke (1899) placed B. antunesii as allied to members of sect. Fissimura and to B. holstii Lindau which is in sect. Barleria but looks similar to species of sect. Fissimura. This placement is clearly wrong, however, since without doubt the protologue description places B. antunesii in sect. Somalia, and Lindau (1895b) suggested that it is allied to B. calophylla and relatives. We are reluctant to select Teixeira 1813 as a neotype of Barleria antunesii in view of the slight discrepancies listed above and in case either of the two specimens seen by Clarke come to light.
This species is morphologically similar to Barleria violascens, and particularly to var. humpatana, but it clearly differs in the densely hairy calyces and bracteoles and the more erect habit. S.Moore (1907a: 91); Obermeyer (1933: 149) Shrub or woody perennial herb, erect, decumbent or scrambling, 10 -300 cm tall; stems with fine white antrorse-appressed or tomentellous hairs, often dense when young, sometimes also with numerous short patent glandular hairs, later glabrescent, mature stems first chestnut-brown then later with grey-brown bark.
In light of this complex picture, we currently consider B. matopensis to be best treated as a single, variable taxon, but a key to the three forms is provided below. Schubert SS100 from the Kaokoveld is unusual in having short antrorse hairs on the beak of the immature capsules, these being glabrous in all other material seen. The only other specimen seen from that region, Schubert SS88, has glabrous ovaries; it is otherwise a good match for SS100. More material is desirable from the Kaokoveld to assess the extent of variation there.

Key to infraspecific variants of Barleria matopensis
1 Outer calyx lobes with white antrorse or tomentellous hairs often restricted to the margin and main veins (2 veins on anterior lobe, midrib on posterior lobe) or to the margin only, glandular hairs usually restricted to the margin or absent, posterior lobe 3 -5.5 mm wide, l:w ratio 2.6 -5.8: 1 (NE Namibia to W Mozambique) . . . . . . . . . .
HABITAT & ECOLOGY. The habitat of the single known specimen was not recorded. The type locality falls within the Karstveld Acacia Tree-and-shrub Savanna vegetation type of Mendelsohn et al. (2002). CONSERVATION STATUS. This species is known only from the type specimen and has not been rediscovered in over 65 years. Assuming that it is indeed a good species (see Notes), it is clearly rare and highly localised and may well prove to be threatened, but in view of the lack of habitat information or population data, it must currently be considered Data Deficient -DD. NOTES. The plants on the type collection appear to represent young regrowth from a perennial, somewhat woody base. Suessenguth & Merxmüller (1955) noted in the protologue the similarity of this species to Barleria matopensis but did not record the differences. The broad glabrous calyx lobes and the small glabrous corollas of B. violacea appear to be diagnostic but we cannot entirely rule out the possibility that this is an aberrant, stunted specimen of B. matopensis. Efforts to rediscover this species have so far been hindered by the rather vague type locality and lack of habitat notes. Suffruticose herb with several decumbent or creeping stems 15 -30 cm long from a woody rootstock; stems hispid, hairs (buff-) golden, ascending or spreading.
Ovary eglandular-and glandular-puberulous or glabrous; style glabrous; stigma 2 -3 mm long. Capsule 2seeded, 15.5 -21.5 mm long, eglandular-and glandular-puberulous or more rarely glabrous; seeds 5.5 -7.5 × 5 -7 mm. Fig. 5. This is a widespread and locally common species in a variety of dry woodland and bushland habitats, with an EOO of over 2,000,000 km 2 . It was assessed as of Least Concern -LC by Darbyshire (2015). It is locally abundant and widespread within the current study region and does not appear to be threatened. NOTES. Barleria mackenii is fairly uniform over most of its broad range across southern Africa, but becomes considerably more variable in its western extremities, particularly in Angola. It is quite possible that more than one taxon is involved here, but from the limited Angolan material seen to date it has not been possible to delimit discrete taxa as the morphological characters seem to vary independently of one another. However, some of the variants are worthy of note; some of this variation is also exemplified in Fig. 5. The form separated as Barleria cunenensis by Benoist (1950) was first described from the Angolan side of the Namibian border at Ruacana but is also recorded in northwest Namibia (e.g. Hochobes MH1448; Kolberg et al. HK1507). These plants have a short fine patent indumentum on the leaves and calyces in addition to the longer, (sub)appressed hairs along the main veins; they also tend to dry a paler green than elsewhere in the range of B. mackenii  Shrub or perennial herb 30 -100 cm tall; mature stems densely white-velutinous, hairs minute, declinate, interspersed with occasional longer appressed hairs; distal internodes patent glandular-pubescent and with sparser white declinate and appressed hairs. Leaves on petiole 4 -16 mm long; blade somewhat coriaceous, ovate (-elliptic) or lanceolate, 3.5 -8 × 1.4 -3.3 cm, base cuneate, attenuate or obtuse, apex acute, attenuate or rarely obtuse, lateral veins 4 -5 pairs; leaf buds densely white-strigulose but mature leaves soon-glabrescent except for sparse strigose hairs along the margin, midrib and sometimes lateral veins beneath, some hairs "anvilshaped" (i.e. biramous with one long arm and one short arm), distal pairs of leaves also glandular-pubescent at least along margin. Inflorescences terminal spikes 2 -8 cm long, often many-flowered and dense throughout or rarely becoming more lax towards base, each cyme within spike single-flowered or cymes at base of spike 3-flowered; bracts, bracteoles and calyces yellow-green to green or bracts sometimes drying darker green-brown; bracts in distal portion of inflorescence held ± erect and (partially) covering the calyces, elliptic or somewhat oblanceolate, rarely lanceolate, 11.5 -22 × (3 -) 4 -8.5 mm, apex acute or somewhat attenuate, pairs of bracts towards base of inflorescence often larger and more spreading, typically 21 -33 × 5 -15 mm, densely glandular-pubescent throughout; cymes often sessile but lowermost pairs can be pedunculate for up to 3.5 (-6.5) mm long; bracteoles held ± erect against the calyx, narrowly elliptic, oblanceolate or lanceolate, 15.5 -20 × 2.5 -5 mm, apex acute, midrib or sometimes 3 main veins prominent; flowers subsessile. Calyx not markedly accrescent, anterior lobe elliptic or subrhombic, 11 -19 × 5.5 -9 mm, base cuneate or attenuate, apex acute or shallowly notched for up to 2.5 mm, surface with 5 -7 prominent subparallel veins; posterior lobe as anterior lobe but marginally larger, apex acute or shortly attenuate, densely glandular-pubescent; lateral lobes lanceolate, 7 -13.5 mm long. Corolla pink, blue or pale purple with whitish throat and tube, 34 -52 mm long, lateral lobes with numerous to sparse mixed glandular and eglandular hairs externally; tube 17 -28 mm long, subcylindrical or throat gradually expanded, mouth 3.5 -6.5 (-7.5) mm wide; lobes in "4+1" configuration, abaxial lobe offset by 5 -9 mm from the remaining lobes, broadly obovate, 11 -18.5 × 7.5 -14.5 mm, apex emarginate; lateral lobes elliptic-obovate or obovate, 11 -18.5 × 8 -14 mm, apices rounded or shallowly emarginate; adaxial lobes narrower, 4.5 -9.5 mm wide. Stamens inserted c. 7 mm from base of corolla tube; filaments ± 31 mm long; anthers 3.3 -4.3 (-4.8) mm long; lateral staminodes to 1.5 mm long, flattened and triangular. Ovary densely glandularand eglandular-puberulous distally; style glabrous; stigma 1.5 -3 mm long, curved. Capsule 2-seeded, 14 -18 mm long including beak 5 -7 mm long, glandularand eglandular-puberulous; seeds 5.7 -6.2 × 5.4 -5.8 mm. Fig. 6G -H. DISTRIBUTION Mendelsohn et al. (2002). CONSERVATION STATUS. This species was assessed as Data Deficient in the protologue, when only two collections were known. However, it is now known to be considerably more widespread in the Kaokoveld region with an EOO of 12,300 km 2 . It occupies dry rocky slopes and riverbeds in arid areas, where human populations and impacts are low. Grazing pressure in some parts of its range may impact seedling recruitment, but this is not considered to be a major threat at present. This species is therefore reassessed here as of Least Concern -LC. NOTES. A review of the Barleria material held at WIND, M and PRE has revealed this species to be more common and widespread than indicated in the protologue. The description is updated accordingly. Much of the material was filed under either B. lancifolia or, more surprisingly, under B. mackenii, although many collections were labelled as a potential new species near B. lancifolia by Mandy-Jane Balkwill (Cadman). Whilst B. grootbergensis is clearly closely allied to B. lancifolia, the welldefined, ± dense terminal spikes with erect bracts and bracteoles partially enclosing the calyces at least in the distal half of the spike, and the more acute, often subrhombic calyces are all characteristic and make this species easy to separate. The glandular hairs on the inflorescence are also longer and often more dense. A few specimens of  (1863: 28); Moore (1902a: 407;1907b: 230); Obermeyer (1933: 147), excl. B. alata;Meyer (1957: 381;1968: 15), pro maj. parte; Compton (1976: 553); Balkwill & Balkwill (1997: Br. ex C.B.Clarke (1901: 53 Perennial herb or usually a subshrub, 20 -150 cm tall, woody towards base, branches varying from prostrate to erect; lower stems densely and minutely white-velutinous, uppermost internodes with ± numerous patent glandular hairs and sparsely to densely puberulent, sometimes with scattered appressed-strigulose hairs. Leaf buds densely white-strigulose and/or -velutinous. Leaves on petiole to 15 mm long; blade lanceolate, narrowly elliptic or ovate, 1.8 -11.5 × 0.7 -3.8 cm (l:w ratio 1.45 -7.5: 1), base attenuate or cuneate, apex acute or rarely obtuse, apiculate, surfaces soon glabrescent except margin and midrib beneath sparsely strigulose; lateral veins 4 -5 pairs. Inflorescences axillary in the distal portion of the branches, cymes 1 -3-flowered, rarely with 2 cymes per axil, often together forming a lax spike; cymes sessile or peduncle to 10 (-25) mm long; bracts foliaceous but often muchreduced at upper nodes, where typically linear or oblanceolate, 11 -20 × 2 -5 mm, often with scattered glandular hairs; bracteoles linear, oblanceolate or narrowly ellipticlanceolate, 6 -20.5 × 0.5 -3.5 mm, patent glandularpubescent, veins strigulose; flowers sessile or pedicels to 4.5 mm long. Calyx weakly accrescent; anterior and posterior lobes equal, elliptic to ovate-elliptic, 7 -20 × 4 -9.5 mm in flower, 12.5 -25 × 9.5 -13.5 mm in fruit, base cuneate or acute, apex rounded to subattenuate or that of anterior lobe often minutely notched, external surfaces ± densely patent glandular-pubescent or rarely these hairs sparse or absent, main veins strigulose, inner surface puberulous, venation palmate or subparallel, prominent; lateral lobes lanceolate, 5 -9.5 mm long in flower, 9 -13 mm in fruit. Corolla 26.5 -48 mm long, blue, mauve or lilac with paler tube, mouth either darker purple or white, whole flower rarely whitish at anthesis, lateral lobes eglandular-and glandularpubescent externally, elsewhere glabrous; tube infundibuliform to narrowly so or almost cylindrical throughout, 13 -18.5 mm long, basal cylindrical portion 3.5 -4.5 mm wide, then rapidly to gradually widening to 4 -12 mm at the throat; limb in "4+1" configuration; abaxial lobe offset by 3.5 -7 mm, obovate, 12 -18.5 × 7.5 -15 mm, apex emarginate or rounded; lateral lobes obovate to elliptic 10 -16 × 7.5 -14 mm, apices obtuse to emarginate; adaxial lobes as lateral lobes but 6 -10 mm wide. Stamens attached 4 -5 mm from base of corolla; filaments 16.5 -25 mm long; anthers 3 -4.5 mm long; lateral staminodes 0.7 -1.3 mm long. Ovary densely eglandular-and glandularpuberulous in distal half; style glabrous; stigma 1.5 -2.5 mm long. Capsule 2-seeded, 14 -17.5 mm long, eglandular-and glandular-puberulous mainly on beak or sometimes with only antrorse-eglandular hairs; seeds ± 6.5 × 5 mm. Fig 6A - Mendelsohn et al. (2002), particularly in most of the sub-divisions of the Nama Karoo and the Acacia Treeand-shrub Savanna. It is largely absent only in the Namib Desert lowlands along the coast, the Succulent Karoo in the southwest and most of the Broadleaved Tree-and-shrub Savanna of the northeast. CONSERVATION STATUS. This is the most commonly encountered Barleria species in Namibia, often being abundant in a range of habitats. It is also widely distributed and fairly common across southern tropical Africa, extending as far east as Southwest Mozambique, with an EOO of over 1,600,000 km 2 . Furthermore, it tends to grow in areas of low agricultural value, such as dry rocky slopes, and it is tolerant of some disturbance, often being common along roadsides. It is assessed as of Least Concern -LC. NOTES. As this is the most widespread and abundant species of Barleria in Namibia, it is no surprise that considerable regional and population-level variation is observed. More than one taxon may be involved, but for the present time we treat it as a single variable species with notes on the most distinctive forms. Plants from southern Karas Region (e.g. Pearson 4022, K!; Craven 2656, WIND!) and extending into the Northern Cape of South Africa (e.g. Leistner 1351, K!) are dwarf shrublets to 50 cm tall with small ovate or narrowly ovate leaves to 3.2 cm long and with l:w ratio 1.45 -2.3: 1. The inflorescence units are always singleflowered and the calyx lobes are often only sparsely glandular-pubescent at maturity, the glandular hairs sometimes restricted to the margins. Similarly broadleaved specimens are occasional from elsewhere in Namibia, particularly in the vicinity of Swakopmund, such as Jensen 207 (WIND!) from Tinkasrivier.

Barleria lancifolia T.Anderson
Further north in Karas Region is a second very distinctive form (e.g. de Winter 3418, K!, M!, PRE!, WIND!; Lensing A183/75, WIND!), in which the calyces are large, (12 -) 15 -20 mm long, extending up to 25 mm long in fruit, and only sparsely hairy externally with few strigulose hairs along the veins and with glandular hairs either absent or (mainly) restricted to the margins. These plants also differ from the southern Karas plants in having more lanceolate leaves (l:w ratio (2.1 -) 2.5 -3.2: 1), larger and deeper-coloured corollas (28 -) 33.5 -50 mm long with a broader throat, and in having only sparsely pubescent capsules, the hairs antrorse-eglandular. A very few specimens from elsewhere in the species' range have sparse or largely absent glandular hairs on the calyx, such as Giess et al. 6245 (M!, WIND!) from Brandberg in Erongo Region.
In the Central Highlands of Namibia, particularly common around Windhoek, the corollas have a purple throat, deeper in colour than the lobes, and the corolla tube is markedly funnel-shaped (e.g. Ellinger ELLI/32, Kolberg HK717, both WIND!). Further north into Kunene and Otjozondjupa, the corollas usually have a white throat and the tube is typically less strongly funnel-shaped to almost cylindrical throughout (e.g. Schmidt 221, M!, WIND!).

Barleria gossweileri
Ovary glandular-and eglandular-puberulous; style glabrous; stigma 1.6 -2.4 mm long. Capsule 2-seeded, (13.5 -) 17 -19.5 mm long including beak (3.5 -) 5.5 -6.5 mm long, glandular-and eglandular-puberulous; seeds 5 -7 × 4 -5.5 mm. DISTRIBUTION Tripp & Darbyshire 2020), and it is likely to be more common within its range than the current data indicate. The locality from the environs of Lobito (from where it was recorded in 1937) may have been impacted by expansion of this port city. However, the large majority of its range has a low human population and its habitat is not favourable to agriculture, hence human pressures are considered to be low and this species is unlikely to be threatened by direct human impact. It is therefore currently assessed as of Least Concern -LC. That said, in the longer term, there is a plausible threat from climate change and increasing aridity in the Namib Desert which may result in longer spells of drought, although the likely impact on this species is not known. NOTES. In the protologue, Moore (1911) noted "the habit is much that of B. alata S. Moore belonging to Sect. Eu- Barleria. It is quite unlike the other known species in Sect. Somalia" (p. 305). Therefore, he did not link this species with Barleria lancifolia. However it has more recently been treated as a variant of B. lancifolia (including by the current first author; Darbyshire 2015) and it is certainly close to that species, but it is resurrected here in view of the fact that is has unique characters of biramous (medifixed or anvil-shaped) hairs on the young leaves, stems, bracteoles and calyces and a glabrous corolla. Barleria gossweileri is often fertile when leafless and has consistently lax inflorescences, the latter character easily separating this species from the related B. grootbergensis. The rank at which it should be recognised is open to debate, but we choose to treat it as a distinct species at present, pending further studies on this group (see introductory note to the B. lancifolia-B. mackenii complex). This species has a comparable range to several other species of Acanthaceae that are restricted to the Angolan extension of the Namib Desert, including Barleria deserticola I. Darbysh. & E.Tripp (see Discussion). 48. Barleria elliptica Benoist (1950: 16 Perennial herb or subshrub, 40 -90 cm tall [fide Teixeira & Andrade 7340, but likely to reach greater height], stems usually puberulent with mixed minute colourless eglandular and glandular hairs throughout or restricted to basal portions, or these hairs rarely largely absent, distal internodes sometimes largely glabrous except for sparse yellow strigulose hairs or pale spreading hispid hairs, often also with scattered short patent glandular hairs. Leaves on petiole 3 -32 mm long or rarely subsessile; blade elliptic or lanceolate, sometimes becoming obovate upwards, largest leaves (5 -) 8 -15 × 2 -5.5 cm (l:w ratio 2 -4.8: 1), base attenuate and with a ± pronounced narrow cuneate extension decurrent onto petiole, apex attenuate or distalmost leaves acute to obtuse; leaf buds densely strigose and puberulent, mature leaves sparsely strigose or hispid along margin, main veins beneath and scattered on adaxial surface, or glabrescent; lateral veins 4 -6 pairs. Inflorescences 1 -3flowered cymes in upper axils, often widely spaced, sessile or cymes at lower fertile nodes pedunculate for up to 12 (-30) mm; bracts foliaceous but reducing and narrowing upwards, those at uppermost nodes typically narrowly elliptic, oblanceolate or linear, 12 -36 × 2 -11 mm; bracteoles linear, then 4 -10 × 0.3 -2 mm, or those of lowermost inflorescences sometimes oblanceolate and up to 11 -19 × 2.5 -5 mm; flowers sessile or pedicels to 3 mm long. Calyx with anterior and posterior lobes subequal, green or brownish, elliptic to lanceolate, 11 -18 × 4.5 -7.5 mm, base cuneate to obtuse, apex acute to rounded or that of anterior lobe shallowly notched, surfaces strigulose to hispidulous along main veins and margin, elsewhere shortly glandular-pubescent and usually also eglandular-puberulent, up to 8 subparallel veins prominent or only 2 on anterior lobe and 1 on posterior lobe prominent; lateral lobes pale, linearlanceolate, 5 -8.5 mm long. Corolla 29 -47 mm long, pink, blue, pale purple or white, lateral lobes pubescent externally with mixed eglandular and glandular hairs; tube 15 -21 mm long, widened above attachment point of stamens or barely so, 4.5 -7 mm in diam. below mouth; limb in weak "4+1" configuration, abaxial lobe offset by 2 -3.5 mm, obovate or broadly so, 13 -21.5 × (7 -) 10.5 -15.5 mm, apex rounded; lateral lobes obovate to broadly so, 15 -24.5 × 7 -14.5 mm; adaxial lobes oblong-obovate, 6 -10.5 mm wide.
Ovary densely puberulous with mixed eglandular and glandular hairs; style glabrous; stigma linear, 1.2 -2 (-2.6) mm long. Capsule 2-seeded, 18.5 -22 mm long including beak 6 -7 mm long, indumentum as ovary; seeds 5.5 -6 × 5 -5.5 mm. CONSERVATION STATUS. This species has a scattered distribution in western Angola and just extends over the border into southern D. R. Congo, with an EOO of 58,250 km 2 . From the evidence to date, it appears to be scarce with highly isolated subpopulations, but this may be a product of incomplete botanical inventory over much of its range. As the specific habitat requirements for this species are currently unclear, it is difficult to assess the threats with certainty. Some of the known historical localities have been impacted by human activities; for example, the area of Capacca near Cubal is intensively farmed except for the steep slopes of the large inselberg to the north of the Cubal -Ganda road, and the Pungo Andongo area has suffered from recent (post-2000) loss of "forest cover" (Mendelsohn 2019, Fig. 8.1). However, if, as some evidence indicates, this species favours rocky ground then the impact from agriculture may be reduced. In view of this uncertainty, it is assessed as Data Deficient -DD but it may prove to be of Least Concern. NOTES. Despite the obvious morphological similarities, Benoist (1950) did not equate his Barleria alata var. amoena with his own B. elliptica published in the same paper. The former has markedly narrow lanceolate leaves (l:w ratio 3 -4.8: 1) and narrow lanceolate outer calyx lobes (l:w ratio 2.5 -3.5: 1), often with only two veins prominent on the anterior lobe and one vein on the posterior lobe. In most other populations of B. elliptica, the leaves are elliptic or somewhat obovate (l:w ratio 2 -2.6: 1) and the outer calyx lobes are elliptic or ovate-elliptic (l:w ratio 2 -2.35: 1), with up to 8 subparallel veins prominent. However, Faulkner A. 403 and Dujardin 421 are somewhat intermediate between the two forms. Moreover, the type of B. elliptica is also somewhat intermediate: it has the narrow leaves (ratio 3.5: 1) of var. amoena but elliptic calyces (ratio 2.3 -2.5: 1) with several nerves prominent. The two forms are therefore considered to be the extremes of a clinal variation and B. alata var. amoena is synonymised here. Gossweiler's specimens from Seles (Gossweiler 9363 and 9374) differ from the other material seen in having a spreading-hispidulous indumentum on the stems and leaves; the type of Barleria elliptica from the same area has sparse ascending long stem hairs.
This species is morphologically close to Barleria lancifolia but differs in lacking the dense white puberulous stem indumentum (puberulous hairs, if present, are colourless in B. alata Perennial herb or subshrub, 30 -80 cm tall, branches often procumbent or decumbent and rooting at the lower nodes, sometimes straggling; stems drying green-black, uppermost internodes sometimes with short retrorse eglandular hairs and patent glandular hairs on two opposite sides, mature stems soon glabrescent. Leaves with unwinged portion of petiole (7 -) 20 -70 mm long; blade thinly papery, ovate or ovate-elliptic, largest leaves (6.5 -) 8 -16 × 3 -7.7 cm, base with a pronounced narrow cuneate extension forming a wing along distal portion of petiole, then attenuate or more abruptly rounded, apex acuminate, surfaces largely glabrous or sparsely strigulose along margin, main veins beneath and scattered on adaxial surface; lateral veins (3 -) 4 -5 pairs. Inflorescences terminal, spiciform, (2 -) 4 -23 cm long, at first contracted but cymose units soon becoming ± widely spaced along rachis, each cyme 1 -3-flowered, subsessile, those in lower portion of spike sometimes aborting early; rachis densely patent glandularpubescent and with retrorse eglandular hairs; bracts rapidly reducing and narrowing up the spike, those midway along rachis oblanceolate or narrowly elliptic, 7.5 -16 (-20) × 2 -5.5 mm, sometimes caducous; bracteoles linear, then 3.5 -10 × 0.5 -1 mm, or those of lowermost cymes sometimes oblanceolate and up to 14 × 3 mm; pedicels 1 -5 (-7.5) mm long. Calyx green with ± paler base, somewhat accrescent, anterior and posterior lobes obovate, anterior lobe 7.5 -13 × 4 -8 mm in flower, up to 18.5 × 9.5 mm in fruit, base cuneate or attenuate, apex rounded or often notched for up to 2 mm, posterior lobe slightly longer, apex rounded or obtuse, rarely subacute, external surfaces patent glandular-and eglandular-pubescent, glandular hairs sometimes mainly along margin, main veins subparallel,  Barleria alata is a species of moist forest, particularly in clearings and along forest margins or in secondary forest, and has also been recorded from coffee plantations. It can also occur in periodically inundated swamp forests. It occurs at 100 -800 m elevation. CONSERVATION STATUS. This species is widespread in the Congolian forests of West-Central Africa, with an EOO of 765,372 km 2 based upon known occurrence data. However, it appears to be rather scarce at least in parts of its range; for example, it is known from only one collection in Gabon and from only one locality in Cameroon. Forest remains widespread within parts of its range and it appears tolerant of or even to favour low-level habitat disturbance, although forest clearance in some parts of its range will almost certainly have led to some local subpopulation declines. In view of its large range, it is here assessed as of Least Concern -LC. NOTES. Heine (1966) correctly concluded that the five syntypes of Barleria alata cited by Moore (1880) represent two distinct species. He was also right that the forest species he treated as B. alata sensu stricto for the Flore du Gabon is distinct from B. lancifolia, a species that Clarke (1899) had erroneously synonymised within B. alata sensu lato, contrary to the Botanical Code (Turland et al. 2018). However, Heine did not formally lectotypify B. alata, thus prolonging the nomenclatural confusion. Furthermore, in his long discussion on the status of B. alata we believe he made two errors. The first was to equate the Pungo Andongo syntypes (Welwitsch 5194 and 5195) with B. lancifolia when in fact they represent an allied but distinct species, B. elliptica (see above). The second was to state that Moore's protologue description was based primarily on Welwitsch 5147, 5148 and 5169, when in fact there are several characters, including the stem indumentum and shape of the calyx lobes, that Moore clearly derived from Welwitsch 5194 and 5195. The original description of B. alata is therefore an amalgamation of the two taxa represented by the five syntypes and it is clear from later literature (Moore 1902a(Moore , 1930) that Moore continued to consider the syntypes and subsequent collections of these taxa to represent a single species. On examining the BM material of B. alata in November 1933, Amelia Obermeyer ("AAO 8/11/33") annotated Gossweiler 6531 with "Not!" adjacent to the original determination of Barleria alata S.Moore, adding "prob. n. sp.". "Not" is also written in the same handwriting next to "Barleria alata S.Moore" at the foot of each of the three syntypes Welwitsch 5147, 5148 and 5169. By inference, Obermeyer must have considered Welwitsch 5194 and 5195 to represent true B. alata, although her basis for this decision is unclear. It is perhaps because Welwitsch 5195 is the largest of the five syntype specimens at BM and is annotated with a full Latin description, transcribed from Welwitsch's notes. This specimen is the only one to have been subsequently curated in a type cover, but this does not mean that it should automatically be chosen as the lectotype. We have chosen instead to lectotypify B. alata using Welwitsch 5148. This has been done to promote nomenclatural stability, in view of Heine's (1966) application of the name B. alata and in view of the fact that the second species, represented by Welwitsch 5194 and 5195, already has a name: B. elliptica Benoist. Furthermore, the name B. alata best suits the species represented well by Welwitsch 5148 in view of its wing-like leaf base.
Barleria alata differs from B. elliptica in the mature stems being glabrous (vs usually puberulent); the leaves having longer petioles and more markedly rounded leaf base above the decurrent wing; the terminal spiciform thyrse being better developed with more rapidly reduced bracts upwards; the outer calyx lobes being obovate, (vs elliptic or lanceolate) with longer hairs (pubescent vs puberulous); and the corolla having a more strongly offset abaxial lobe.

50a. Barleria kacondensis S.Moore subsp. kacondensis
Plants conspicuously hairy throughout, particularly on the stems, abaxial surface of the leaves and on the calyx lobes, hairs persistent; stems usually muchbranched. Fig. 7A -D. DISTRIBUTION Subsp. kacondensis has a restricted range in southern Angola, with an EOO of 20,492 km 2 based on known occurrence data. Most of the records are from the vicinity of the type locality at Caconda and from the vicinity of Menongue. It is not known to occur in any protected areas, and its range coincides with areas that have experienced some of the most extensive losses of "forest cover" in Angola between 2000 and 2015 (Mendelsohn 2019, fig. 8,1), particularly in the vicinity of Menongue and in the western part of its range. As this species prefers open grassland and wooded grassland, it may be able to tolerate some woodland clearance, but as most of this woodland loss has been through conversion to agricultural land, the population of this species is highly likely to be in decline. Based on current evidence, it is known from fewer than 10 locations with a continuing decline in quality and extent of habitat but its range falls just outside the threshold for Vulnerable under criterion B1 of IUCN (2012). It is therefore assessed as Near Threatened -NT B1ab(iii). NOTES. The BM sheet of Gossweiler 4251 is selected as the lectotype, as it is an informative specimen and was cited by Moore (1911) as being used for the basis of the calyx measurements in the protologue. The LISC sheet of Gossweiler 4147, which is annotated by Spencer Moore, bears a different collecting locality name to the syntype at BM under the same collecting number, although the two localities are essentially the same. Further, the LISC sheet is in flower bud only whereas both the BM and K sheets (the latter of which has no locality information on the label) are in fruit; the LISC sheet is therefore not considered to be an isosyntype.
This subspecies could potentially be mistaken for pale-flowered forms of Barleria mackenii (see species 44 above) as they share broad, ovate calyces with hairy palmate venation and large corollas with a broadly funnel-shaped tube. However, B. kacondensis is easily separated from that species by the suffruticose habit, coarser stem indumentum, glabrous corolla, glandular staminal filaments and glabrous, 4-seeded fruits.
Plants sparsely and inconspicuously hairy or glabrescent; stems unbranched or few-branched. Fig. 8. RECOGNITION. Subsp. glabrescens differs from subsp. kacondensis primarily in being less densely and conspicuously hairy particularly on the stems and calyces, with the hairs less persistent such that the fruiting plants are glabrescent, but it also differs in the stems arising from the woody rootstock being fewer branched, and in the apex of the posterior calyx lobes being acute or obtuse, not attenuate as is frequent in subsp. kacondensis. DISTRIBUTION glabrescens could be confused with that species. However, it differs in several notable characters: (1) the staminal filaments are covered in subsessile glands throughout, in addition to being glandularpuberulous at the base, whilst only the latter is present in B. benguellensis; (2) its stems are erect whilst those of B. benguellensis appear to be trailing and ± weakly decumbent; (3) the cymes are more widely spaced at least proximally and those at the lowermost fertile nodes are held on long peduncles; these are absent in B. benguellensis where the cymes are all subsessile and congested into a dense terminal spike; (4) the corolla lobes are considerably broader, the abaxial and lateral lobes being broadly obovate to obovate-orbicular in shape rather than oblong-elliptic to oblong-obovate in B. benguellensis. We also consider it very likely that B. benguellensis will have a 2-seeded capsule (as per its close allies B. polyneura and B. violascens) whereas in B. kacondensis the capsule is 4-seeded.
Moreno considered his numbers 312 and 314, growing side by side at the same locality, to be two different taxa. This was presumably because of the variation in flower colour from cream (312) to pale pink (314). There is also a slight difference in calyx shape, those on 312 being more ovate, but they clearly belong to the same taxon. In subsp. kacondensis, the flowers are usually white. 51. Barleria thunbergiiflora I. Darbysh. sp. nov. Type: Angola, Moxico Prov., confluence of Cuito R. and Calua R., fl. 25 Feb. 2016, Goyder 8343   currently known given the fact that its preferred habitats are widespread there. Of the two populations found by D. Goyder (pers. comm.), only a single patch of this species was found at the type locality, but at the second locality (his collection 8952) the population was much larger and scattered over several kilometres. The perched valley-grasslands on sand that this species occupies are nutrient-poor and are not suitable for agriculture, so there are no obvious threats. Increased frequency of burning, observed in some areas (D. Goyder, pers. obs.), may result in gradual ecological changes over time but the human population remains low within much of its range at present. It is therefore assessed as of Least Concern -LC. ETYMOLOGY. The species epithet "thunbergiiflora" refers to the fact that the flowers of this species superficially resembles the genus Thunbergia in having large, funnel-shaped corollas and in the large calyx lobes resembling the conspicuous paired bracteoles in Thunbergia. Indeed, the type specimen of this plant was first identified as a Thunbergia in the field. NOTES The habitat was not recorded on the single specimen seen, which was collected from c. 1400 m elevation. CONSERVATION STATUS. As the status of this species is not fully resolved and its habitat requirements are unknown, it is assessed as Data Deficient -DD. NOTES. This is a very striking species known only from a single fruiting specimen. The dense contracted fruiting spikes are reminiscent of Barleria benguellensis but it differs from that species in the much larger leaves with a rounded or subcordate base, the elliptic calyces with a cuneate base (not ovate with base rounded or subcordate), and the much stouter stems which appear to be erect (not trailing).
Barleria benguellensis is also likely to have 2-seeded capsules like the closely related B. violascens and B. polyneura. Of the 4-seeded species, it is most likely to be confused with B. kacondensis subsp. glabrescens which can have contracted terminal inflorescences and is largely glabrous but that species differs in having much narrower, oblong-elliptic to lanceolate leaves up to 3.6 cm wide, with l:w ratio 3.6 -4.6: 1 compared to c. 2: 1 in the Teixeira specimen, and the compound inflorescences are not nearly so dense as in this specimen. Flowering material of this undescribed species is required.

53.
Barleria eburnea I. Darbysh. sp. nov Dwarf perennial herb, few-to many-branched from a small woody rootstock, sometimes with a short rhizome, with fleshy roots; stems erect or decumbent, 10 -35 cm tall, 4-ridged, glabrous or puberulous mainly on two opposite sides between the ridges. Leaves sessile or petiole to 6 mm long; blade somewhat coriaceous, glaucous-green but drying dark green or green-black, elliptic to narrowly so, ovate-elliptic or obovate-elliptic, 4.5 -6.7 × 1.6 -2.7 cm (l:w ratio 2 -3.5: 1), base cuneate or attenuate, margin entire, apex acute to obtuse, apiculate, surfaces glabrous; lateral veins 4 -8 pairs, these and reticulate tertiary venation prominent beneath. Inflorescences of single-flowered cymes in the upper axils; bracts foliaceous but those towards stem apices much reduced, typically narrowly oblong-elliptic, 20 -33 × 3.5 -8 mm; peduncle 1 -6.5 mm long or cymes at lowermost fertile axils with peduncle up to 13 mm long; bracteoles ascending-arcuate, subulate to oblanceolate, (13.5 -) 17 -28.5 × 2.5 -5 (-7.5) mm, markedly conduplicate, apex acute or rounded, surfaces glabrous; pedicels 1.7 -3.5 mm long. Calyx drying dark green, green-brown or green-black with darker palmate venation, accrescent; anterior lobe broadly ovate, 24 -28 × 14 -16.5 mm in flower, up to 30 × 23 mm in fruit, base cordate, margin entire, apex obtuse, rounded or emarginate, external surface glabrous or with few short hairs along margin, internal surface sometimes puberulent; posterior lobe as anterior lobe but 27 -32.5 mm long in flower, up to 33.5 × 26 mm in fruit, apex obtuse or acute; lateral lobes linear-lanceolate or lanceolate, 7 -8 mm long in flower, up to 10 mm long in fruit, puberulent. Corolla 28 -31 mm long, white, cream or pale yellow with purple in throat, glabrous externally; tube 10.3 -11.7 mm long, broadly cylindrical below insertion point of stamens where 3.5 -4.5 mm in diam., narrowly funnel-shaped above, mouth 5.5 -6 mm in diam.; limb subregular, abaxial lobe broadly obovate, 16 -20 × 12 -13 mm, apex emarginate; lateral lobes oblong-obovate, 18 -19 × 11.5 -13 mm, apices rounded or emarginate; adaxial lobes broadly obovate, 15 -16.2 × 11 -13 mm. Stamens inserted 4 -5 mm from base of corolla tube; filaments 6.5 -8 mm long; anthers ± 3.5 mm long, held at corolla mouth; lateral staminodes well developed, 2 -2.7 mm long. Pistil glabrous; stigma linear, c. 3 -3.5 mm long, curved. Capsule 4-seeded, 23 -24 mm long including beak 5 mm long, glabrous; seeds c. 8 mm long. Figs 10 & 11A. RECOGNITION. Barleria eburnea is superficially similar to B. polyneura but differs in the stems being erect or decumbent (vs trailing or at most weakly ascending); the capsule being 4-seeded (vs 2-seeded); the leaves being ± elliptic with base cuneate or attenuate (vs leaves ± ovate with base rounded, subcordate or obtuse); the staminal filaments being shorter (6.5 -8 mm long, vs 10.5 -12 mm) and the bracteoles being longer and ascending-arcuate, (13.5 -) 17 -28.5 mm long (vs spreading, 5 -18 mm long). It is similar to B. pabularis in corolla morphology but differs in the outer calyx lobes being broadly ovate with base cordate and external surface largely glabrous (vs oblong-ovate with base rounded and external surfaces glandular-pubescent in B. pabularis), in the flowers being less markedly aggregated into a terminal spike, and in the bracteoles being narrower, 2.5 -5 (-7.5) mm wide, subulate to oblanceolate and conduplicate (vs bracteoles more broadly oblanceolate, 6 -10 mm wide, and not conduplicate). DISTRIBUTION This species is fairly widespread in the miombo woodlands of central and southern Angola, with an EOO of 59,983 km 2 based on current evidence. This is well in excess of the maximum 20,000 km 2 for threatened taxa under IUCN Criterion B1. Although few collections are known, with only six confirmed locations to date, this is likely to be a reflection of the highly incomplete botanical inventory of central Angola rather than of this species' actual abundance. Large areas of its EOO have been degraded or transformed due to high population densities throughout its range (Mendelsohn 2019, Figs. 8.1 & 8.8). Much of the woodland cover of western Bié Province, for example, was cleared for crops in the 1950s -1970s prior to the civil war (Mendelsohn 2019). However, this species appears, from the limited evidence available, to be able to tolerate some disturbance as it has been recorded from degraded wooded grassland. It is therefore provisionally assessed as Least Concern -LC, but with more data on its current range and threats desirable to help confirm this assessment. ETYMOLOGY. The species epithet "eburnea", meaning "ivory white", refers to the corolla colour of this species. NOTES. This species has previously been confused in herbaria with Barleria polyneura and the two are superficially similar but are easily separated by a number of characters as listed in the Recognition section above and they are unlikely to be closely related, particularly based on differing seed number. The small flowers of B. eburnea, with a short corolla tube and correspondingly short stamens, is quite striking. The closest species in this regard is B. pabularis but that species has glandular hairs present on the calyces and has a more congested inflorescence with larger bracteoles and so looks quite unlike B. eburnea (see Fig. 11). S.Moore (1911: 307;1930: 135); Klopper et al. (2006: 4); Makholela (2008: 22 Dwarf perennial herb, several branched from a woody rhizome, with reddish fleshy adventitious roots; stems erect, decumbent or procumbent, 5 -20 cm tall, unbranched or few-branched, 4-angular, spreadingpubescent on two opposite sides between the ridges and with or without sparse to numerous glandular hairs.

Barleria pabularis
Leaves sessile or petiole to 7 mm long; blade narrowly oblong-elliptic to oblanceolate, 7.8 -10.8 × 1.9 -3.5 cm (l:w ratio 3.8 -5: 1), base cuneate or attenuate, margin entire, apex acute to rounded, apiculate, surfaces glabrous or margin, midrib and main veins beneath strigulose; lateral veins 5 -6 pairs. Inflorescences of singleflowered cymes aggregated into a terminal few-flowered head; bracts oblanceolate or oblong-elliptic, 27 -56 × 11.5 -21 mm; cymes sessile or peduncle to 2 mm long; bracteoles ascending, oblanceolate, 21 -34 × 6 -10 mm, apex usually rounded or obtuse, margin and midrib strigulose, surfaces with sparse to numerous glandular hairs or largely glabrous; pedicels 2 -2.5 mm long, puberulous. Calyx drying dark green, green-brown or blackish-green; anterior and posterior lobes subequal, oblong-ovate, 26 -30 × 14.5 -18 mm, base rounded, margin entire, often revolute, apex of anterior lobe emarginate or rounded, often revolute, posterior lobe obtuse, external surfaces glandular pubescent or sparsely so, main veins and margin strigulose; lateral lobes straw-coloured, lanceolate, 11.5 -12.5 mm long, glandular-puberulous. Corolla [only one measured] c. 35 mm long, white, cream-coloured or "yellow with blue throat", glabrous externally; tube 13 mm long, cylindrical below insertion point of stamens where 4 mm in diam., widened above, mouth 5.5 -7 mm in diam.; limb subregular, lobes broadly obovate, abaxial lobe 19.5 × 19 mm, lateral lobes 21 × 17.5 -18 mm, adaxial lobes 19.5 × 15.5 mm, apices emarginate. Stamens  The EOO of this species, based on known occurrence data, is 30,621 km 2 and it is known from five localities, but botanical exploration has been very limited to date within much of its range. Although information on its habitat preferences is very limited, it does appear to tolerate some disturbance as it has been recorded from open pasture land. That said, the west and central parts of its EOO are heavily populated with much ongoing degradation or transformation of natural habitats (Mendelsohn 2019, Figs. 8.1 & 8.8), and this may have impacted some subpopulations of this species, but this requires confirmation. Given the relatively large EOO, this species is provisionally assessed as of Least Concern -LC, but with more information desirable on its current abundance, range and threats. NOTES. Benoist (1950) identified Gossweiler 11975 from Huambo as Barleria welwitschii. The duplicate of this specimen at BM is not very informativethe calyces are mainly hidden behind the bracts and so not easy to observe and there are no corollas present. However, the glandular hairs on the inflorescence are much sparser than in the type specimen of B. welwitschii, and it is a better match for B. pabularis. These two species are similar but B. pabularis is separated by its larger bracts and bracteoles and in particular its larger, more ovate outer calyx lobes with a rounded (not obtuse) base and with a less dense glandular indumentum. This species has a rather untidy appearance due to its low growth habit (perhaps related to its preference for grazed or fire-prone savannas) with large foliage and bracts which can partially hide the flowers; see Chavaca,fl. & fr. 6 April 1973, BR*, K!) has a similar growth habit but it lacks a glandular indumentum on the calyces and also has proportionately broader, elliptic or obovate leaves and more ovate-cordate outer calyx lobes. More material is needed from that locality to determine whether this is a form of Barleria pabularis or a different species. Dwarf perennial herb with a small woody rhizome and fleshy adventitious roots; stems erect or soon decumbent, 10 -30 cm tall, unbranched or few-branched, 4ridged, shortly spreading-pubescent particularly on two opposite sides between the ridges. Leaves on petiole to 16 mm long; blade oblanceolate or elliptic-oblanceolate, 6 -11 × 2.4 -4.9 cm (l:w ratio 2.8 - 3.4: 1), broadest towards stem base, base long-attenuate, margin entire, apex acute or obtuse, surfaces glabrous except midrib above pubescent and main veins beneath sparsely strigulose; lateral veins 5 -6 pairs. Inflorescences of single-flowered cymes aggregated into a few-flowered head or spike up to 5 cm long; bracts oblanceolate, those at base of spike up to 52 × 14 mm, those towards apex of spike typically 19 -31 × 6 -9 mm; peduncle of each cyme 1 -4.5 mm long, puberulous; bracteoles held erect, oblanceolate or linear, 11 -22 × 2 -5.2 mm, apex acute to rounded, surfaces glandular-pubescent, margin and main veins strigulose; pedicels 1.5 -4 mm long. Calyx drying brown towards apex, paler towards base; anterior and posterior lobes subequal, obovate or obovateelliptic, 18 -25 × 8 -16 mm, base obtuse, margin entire, apex of anterior lobe emarginate, rounded or obtuse, posterior lobe obtuse, external surfaces glandularpubescent and with interspersed short eglandular hairs, main veins and margin strigulose; lateral lobes strawcoloured, linear-lanceolate, 6.5 -7.5 mm long, puberulous. Corolla 32 -36 mm long, white, glabrous externally; tube 15 -16.5 mm long, cylindrical below insertion point of stamens where 3.5 mm in diam., barely widened above, mouth 5.5 -6 mm in diam.; limb subregular, lobes broadly obovate, 15.5 -19 × 12.5 -16 mm, apices emarginate, lateral lobes somewhat larger than the other lobes. Stamens inserted 5.5 -7 mm from base of corolla tube; filaments 8 -8.5 mm long; anthers held in corolla throat, ± 4 mm long; lateral staminodes 1.3 -1.6 mm long. Pistil glabrous; stigma linear, ± 1.9 mm long. Capsule not seen. DISTRIBUTION. Endemic to North Angola (Malanje Prov.), known only from the type specimen; Map 1.
HABITAT & ECOLOGY. The habitat was not recorded on the specimens seen; Teixeira and Andrade made the note "terrenos 20" but we have not had access to the associated habitat description. However, Aguiar & Diniz (1972) produced a vegetation map of the western Cela plateau and noted the natural vegetation to be dominated by miombo woodland (Julbernardia, Brachystegia and Isoberlinia spp.) assemblages. It occurs at c. 1600 m elevation. CONSERVATION STATUS. This species is currently known from two historic locations c. 150 km apart. It was recorded as frequent by Teixeira & Figueira (their number 5911) at Cela in 1961 but this area is now heavily settled and with extensive conversion of natural habitats to both subsistence and commercial agriculture, as evidenced in Google Earth imagery. Even in the early 1970s, this area was dominated by farmland and secondary vegetation (Aguiar & Diniz 1972), and there has been some marked "forest cover" loss between 2000 and 2015 in the southern part of this region (Mendelsohn 2019, Fig. 8.1). The locality of the Wellman collection in Huambo Province is rather vagueit lies south of the Mount Moco Special Reserve in an unprotected area. Palacios et al. (2015) report high rates of miombo woodland loss in Huambo, reducing from 78.4% province-wide in 2002 to only 48.3% in 2015, with much of the reduction attributable to expansion of croplands. Given the high level of threat to natural habitats within its range and the apparent scarcity of this species, it is provisionally assessed as Endangered -EN B2ab(iii) but with more information on current range, abundance and threats desirable. ETYMOLOGY. Barleria louiseana is named in honour of my [I. D.'s] wife Louise, to thank her for her unending support. NOTES. This very distinctive and attractive species is known from only three collections. The two Teixeira specimens are excellent material and are clearly distinct from the most likely confusion species, Barleria welwitschii, using the characters listed in the Recognition section. The Wellman specimen is very poor material but is a good match for the two Teixeira collections particularly in the distinctive inflorescence indumentum. The description of the corolla is somewhat incomplete because there was no material available for dissection, hence only approximate measurements are given for some of the corolla dimensions.
NOTES. This section comprises 12 species, confined to Africa and Arabia with centres of diversity in the fireprone miombo woodlands of East Africa and Angola. It is easily recognised by having the combination of a stellate or dendritic indumentum, dense terminal heads or spikes of flowers and 2-seeded capsules without or with only a short beak and with a largely membranous septum (Balkwill & Balkwill 1997;Darbyshire 2008;Darbyshire et al. 2019b). In Angola and Namibia, a stellate or dendritic indumentum is confined to sect. Stellatohirta.
In addition to the five species of sect. Stellatohirta enumerated here, Barleria purpureotincta I. Darbysh. was also noted in Flora Zambesiaca to occur in Angola (Darbyshire 2015: 90). This record was based on the specimen Pocock 214 which was collected on 9 May 1925, with the locality recorded as "Rhodesia-Angola, woodland near Kassassa". However, based on the itinerary of Mary Pocock's travels set out in Balarin et al. (1999) and her diary entries reproduced in Dold & Kelly (2018), it is clear that she did not cross from Zambia into Angola until approx. 12 May 1925 (she was in the border area on 11 th Mayher numbers 248 onwards) and, although Kassassa has not been precisely located, it is believed to have been on the Zambian side of the border near Lukona. Tellingly, Pocock 241, a specimen of Drosera indica L., is labelled as "between Kassassa and Angolan border" (Balarin et al. 1999). In light of this information, B. purpureotincta reverts to being a Zambian endemic. That said, its range is very likely to extend into the highly under-botanised eastern Moxico Province of Angola and so this species is included in the key to sect. Stellatohirta here.
With the exception of Barleria taitensis subsp. occidentalis, the species of sect. Stellatohirta in Angola are known from few collections, and further material is highly desirable.
HABITAT & ECOLOGY. The habitat for this species was not recorded by Welwitsch. CONSERVATION STATUS. This species is known only from the two syntype collections from 1857, when Welwitsch recorded it from two areas in the river valleys of Malanje Province. This area of Angola has not been well botanised since the early expeditions of Welwitsch, hence the full range and abundance of this species is not known. Further, the exact localities of these collections have not been pinpointed and the habitat for this species is not known. Therefore, a full threat assessment is not possible and it must currently be assessed as Data Deficient -DD, although there has certainly been some extensive habitat modification within its range as evidenced by Google Earth imagery. NOTES. The wispy white stellate indumentum of the abaxial surface of the leaves and young bracts, contrasting markedly with the long golden, predominantly simple hairs on the calyces, are highly distinctive in this species, as is the marked heterophylly, with the distal leaf pairs being linear-lanceolate. 59. Barleria stellato-tomentosa S.Moore (1880: 268); Clarke (1899: 161); Hiern (1900: 816); Benoist (1950: 18);Klopper et al. (2006: 4); Makholela (2008: 22 Suffruticose herb with fewseveral erect stems from a woody rootstock, 30 -70 cm tall; stems covered in golden-brown dendritic hairs, these either elongate and with only a short arm or more squat and with a long ascending arm. Leaves subsessile or petiole to 9 mm long; blade discolourous, dark above where usually drying dark grey-brown, pale green beneath, somewhat heterophyllous, blades towards stem base elliptic, 5.7 -8.8 × 2.4 -3.8 cm (l:w ratio 1.8 -2.4: 1), those in upper portion of stems narrowly oblongelliptic, lanceolate or somewhat oblanceolate, 4.2 -7.6 × 1 -2.4 cm (l:w ratio 2.7 -4.9: 1), base cuneate or obtuse, margin entire, apex acute to rounded, apiculate, upper surface with short-to long-armed stellate hairs, at first numerous but can be caducous, lower surface with numerous short-to long-armed stellate hairs throughout at least when young and with short inflorescences a dark appearance whilst in B. subglobosa the inflorescence is golden-brown or golden-green in the dry state. That said, Barbosa et al.
(12020) has less markedly coloured bracts than the other material of B. stellato-tomentosa. The distributions of these two species are separated by the central highlands of Angola.
On Gossweiler 9290, the corolla is recorded as being "ochra [sic.] yellow", but F. Welwitsch (his 5165) recorded the flowers as violet-blue, a more usual colour for species in sect. Stellatohirta. The flowers on Gossweiler 9290 are small and some are witheredit is possible that the colour description is based on withered corollas that can take on an orange-brown hue.
60. Barleria subglobosa S.Moore (1911: 307;1930: 135); Klopper et al. (2006: 5); Makholela (2008: 22 Suffruticose herb or subshrub, sometimes rhizomotous, with fewseveral erect stems from a woody rootstock, 20 -90 cm tall; stems densely covered in golden-brown long-armed dendritic hairs, the arm ascending, and interspersed paler stellate hairs. Leaves on petiole 4 -18 mm long; blade discolourous, dark above where usually drying dark brown, pale green beneath, somewhat heterophyllous, most leaves narrowly oblong-elliptic or lanceolate, 6 -10.8 × 1.7 -3.5 cm (l:w ratio 3.1 -5.2: 1) but basal-most leaves more elliptic, shorter and with l:w ratio typically 2: 1, base cuneate, margin entire, apex acute or obtuse, upper surface with long-armed stellate hairs, at first numerous but can eventually be caducous, lower surface with numerous long-armed stellate to dendritic hairs throughout at least when young and persisting along main veins and margin, hairs at first golden-brown, the stellate hairs becoming paler buff-coloured with maturity; lateral veins 5 -7 pairs, slightly impressed above, these and reticulate tertiary veins prominent beneath. Inflorescences terminal, subglobose or becoming conical in fruit, 2 -4.5 × 2 -3.7 cm; outermost bracts ovate to suborbicular, 15 -29 × 8 -22 mm, base rounded, apex rounded to acute, external surface with dense goldenbrown dendritic hairs and with prominent pinnatereticulate venation; bracts within the head gradually reducing in size and width, resembling bracteoles; bracteoles held erect and clasping the calyx, obovate to oblanceolate, 17 -23 × 4 -9.5 mm, margins often with bulbous based dendritic hairs. Calyx drying pale brown with darker green-brown or pinkish apices, somewhat accrescent; abaxial lobe oblong-obovate, 15.5 -22.5 × 6 -11 mm, base cuneate-attenuate, margin entire, apex with two broadly triangular lobes 2.5 -8.5 mm long, external surface with numerous golden-brown long-armed dendritic hairs especially along veins and margin, sometimes sparse towards base, palmate main veins prominent; posterior lobe as anterior lobe but elliptic-rhombic to obovate-rhombic, apex acute, external surface often with hairs restricted to margin and apex; lateral lobes linearlanceolate, 12 -14.5 mm long, held tightly against pistil, golden-sericeous, only those hairs along midrib with a dendritic base. Corolla blue, purple or lilac, 28 -39 mm long, glabrous externally or with very few hairs at apex of lateral lobes; tube 17 -21.5 mm long, cylindrical or somewhat broadened towards mouth; limb subregular; lobes broadly obovate, abaxial and lateral lobes c. 12 -17 × (6 -) 9 -11.5 mm, apices rounded; adaxial lobes marginally narrower. Stamens inserted c. 10 -11 mm from base of corolla tube; filaments 11 -14 mm long, pubescent in proximal half; anthers shortly exserted, 2.5 -2.8 mm long; lateral staminodes 1.2 -1.6 mm long, pilose, antherodes vestigial, to 0.2 mm long. Pistil glabrous except for dense tuft of minute crisped pale hairs at attachment point of style; stigma linear, 1.9 -2.5 mm long. Capsule 13.5 -14.5 mm long including beak 1.5 -2.5 mm, glabrous; seeds 7 -7.5 × 5.5 -6.2 mm. DISTRIBUTION. This species is endemic to southwestern Angola (Benguela, Cuando Cubango and Huíla Provs.) HABITAT & ECOLOGY. Barleria subglobosa is recorded from dry miombo (Julbernardia) woodland and from bushland on sandy soils, at 1000 -1450 m elevation. CONSERVATION STATUS. Based upon current evidence, this species has a highly restricted range in southwestern Angola with an EOO 19,753 km 2 . None of its known localities are protected, and extensive areas within its EOO have been highly impacted by dense settlement and agricultural activities. Indeed, northern Huíla and northwestern Cuando Cubango Provinces experienced some of the highest rates and most widespread loss of "forest cover" in Angola between 2000(Mendelsohn 2019. With regard to the four known locations for this species, the area of Capacca (Capaca) near Cubal is intensively farmed except for the steep slopes of the large inselberg to the north of the Cubal -Ganda road. Similarly, the locations at Cuchi and Capelongo are now transformed by settlement and agriculture. With a continuing decline in quality and extent of habitat, it is provisionally assessed as Vulnerable -VU B1ab(iii). However, parts of this species' range have been unexplored botanically away from the few main transport routes, and more information on the range and abundance of this species is desirable. NOTES. There is very limited flowering material of this species available; most of the floral measurements are based on the two Mendes collections but the lower size ranges for the lobes are based on Moore's (1911) description in the protologue.
Capsule not seen. DISTRIBUTION This species is, to date, known only from a very small range in the area west of Menongue and around and to the south of Capelongo, with an EOO 4,613 km 2 . Despite its large, showy flowers, it has only rarely been collected and this species has not been recollected during recent surveys of the miombo woodlands of this region within the past decade, although these have been far from exhaustive. The northwestern part of its EOO in the vicinity of Capelongo has been highly impacted by intensive agricultural activity and settlement, with very little intact natural vegetation as evidenced by Google Earth imagery. A significant reduction in "forest cover" between 2000 and 2015 is evident in this area and particularly around Menongue (Mendelsohn 2019, Fig. 8.1). Intact miombo woodland is more extensive in the south and east of its range away from the few main transport routes. Based upon current evidence, this species is provisionally assessed as Endangered -EN B1ab(iii), but with more information desirable on its current range and abundance. NOTES. Barleria buddleioides is easily recognised by its distinctive foliage, the slender leaves being coriaceous and markedly discolorous, with the undersurface completely covered in a dense pale stellate indumentum whilst the upper surface is glabrescent. From the limited material seen, the inflorescence and corolla size appear to be variable and the inflorescence indumentum also varies in colour and hair length. Santos 2961 and ?de Menezes 3929 represent a small-flowered form (lower corolla measurements) with correspondingly small inflorescences which have more elliptic outermost bracts and rather short, oblong-obovate calyces. The other collections seen, including the type, have much larger corollas and correspondingly large inflorescences with broadly obovate outermost bracts and with elongate oblongelliptic or -lanceolate calyces.Two taxa may be involved but we consider it more likely that these are just two extremes of a range of variation within a single taxon.
There is a Baum specimen of this species at Kew which is likely to be an isotype but it lacks further data including a collection number.

NOTES.
The type specimen of this early name in Angolan Barleria has not been found. However, from the protologue description, we suspect that B. macrolemma may be a species of Petalidium. Peyritsch refers to his plant having conspicuous valvate, pale and slightly translucent bracts that enclose the flower which has a subequally 4-lobed calyx; he likens the bracts to the outer calyx lobes of typical Barleria. This could certainly apply to Petalidium, and the two genera are sometimes confused for this reason. Wawra's plant was mainly in fruit and there is very little description of the flowers, although Peyritsch does mention that it has four fertile stamens which would fit for Petalidium, as would the 2-seeded capsule which is ovate and shape and with a short stipe.

Discussion
Species richness and endemism of Barleria in Angola and Namibia Excluding incompletely known taxa, sixty-seven taxa in 59 species of Barleria are recorded in Angola and Namibia (Table 3). Surprisingly, despite having a land border of 1,427 km with contiguous habitats and two shared phytochoriathe Kaokoveld Centre of Endemism and the Zambesian Regional Centre of Endemismonly seven taxa of Barleria (c. 10%) are shared between the two countries. This can be attributed in part to under-collecting in southernmost Angola; for example, B. damarensis, B. lancifolia, B. lugardii and B. matopensis are all recorded from very near to the Angolan border in northern Namibia and are likely to extend into neighbouring Angola. However, this low level of overlap is also a reflection of the markedly high rates of local endemism in Barleria and conversely few truly widespread taxa (Balkwill & Balkwill 1998;Darbyshire & Luke 2016;Darbyshire et al. 2019aDarbyshire et al. , 2019b. Rates of endemism or nearendemism (i.e., species that are largly confined to one country but just extend beyond the political border) for Barleria are high in Namibia, at nearly 50%, and even more so in Angola, at over 70%. If the two countries are combined, then three quarters of taxa of Barleria are entirely or largely restricted to this region (Table 3). Similarly high rates of endemism have been noted in other genera of Acanthaceae in the region, including Monechma Hochst. (Munday complicated by marked differences in collecting density between and within the two countries. Angola is, in general, much less thoroughly botanised than Namibia. In fact, it is the least intensively inventoried country in southern Africa for plants, with the north and east of the country being amongst the regions least well represented by botanical collections in continental Africa (Goyder et al. 2018;Goyder & Gonçalves 2019). This undercollection is exacerbated in the study of Barleria by the loss of a significant portion of the historical Angolan Acanthaceae collections from both Angolan and Portuguese institutions during the civil war (see Introduction, Darbyshire et al. 2019a). Extant collections of Barleria in Angola are largely concentrated from the west, particularly along the coastal lowlands and on the Huíla Plateau in the vicinity of Lubango (Fig. 14B) where there has been much active botanical research.

Angola
Despite the limitations of under-collection and data gaps, some preliminary observations on the distributions of Barleria in Angola can be made. The deep aeolian Kalahari Sands that dominate the eastern half of the country (particularly Lunda Norte, Lunda Sul, Moxico and Cuando Cubango Provincessee Thomas & Shaw 1991) are heavily leached and so of low fertility (Goyder & Gonçalves 2019). This results in low species richness in most plant groups, particularly in those that favour a high soil nutrient content, including Acanthaceae (Darbyshire et al. 2020a). Hence, whilst this area is severely under-collected, it is very likely to host low diversity of Barleria, as our preliminary results suggest (Fig. 14C, Table 4). Only one endemic species of Barleria is known to occur in this area: the newly described B. thunbergiiflora. Goyder & Gonçalves (2019) note a small but poorly understood endemic element to the flora of this region. In contrast, the more fertile soils of the central highlands and plateaus and the river valleys that drain them support a higher diversity of Barleria. Of particular note is the Huíla Plateau and Escarpment (a in Fig. 14C), a known centre of plant endemism (Exell & Gonçalves 1973;Linder 2001;Figueiredo 2008). Huíla Province is noted as the administrative region with the highest taxon richness for Barleria ( Table 4). The Lubango area is particularly noteworthy as the only half-degree-square to hold more than 10 Barleria taxa. The Lubango Highlands (Serra da Chela) potentially hold as many as 200 endemic plant species (Goyder & Gonçalves 2019), and several endemic or range- Fig. 14. Distribution of Barleria in Angola and Namibia. A Administrative regions of Angola and Namibia (see Table 4 for full names of Angolan Provinces and Namibian Regions); B georeferenced collections of Barleria seen by the authors (red circles); C taxon richness per half-degree-square for Barleria; squares with 6 or more taxa are highlighted, a = Huíla Plateau and Escarpment including Lubango Highlands, b = Angolan Kaokoveld Desert, c = Namibian Kaokoveld, d = Brandberg and western vicinity, e = Outjo-Otjiwarongo area, f = southeast Karas region.
with highest species richness and so of high conservation importance (Frazão et al. 2019). Parallel radiations within Acanthaceae, e.g., in the genus Petalidium, further exemplify the botanical importance of these two regions. The Lubango Highlands have also been noted as a critical area for diversity in the legume genus Vigna Savi, contributing significantly to the gene pool for Crop Wild Relatives of important crop species such as the cowpea, V. unguiculata (L.) Walp. (Catarino et al. 2021).

Namibia
Namibia has much more complete botanical coverage than Angola, and this may partially explain the appearance of generally higher species richness per half-degree-square than in Angola ( Fig. 14C) despite its lower total number of species (Table 3). There are still many under-collected areas in Namibia, such as the more inaccessible mountains of the extreme northwest, and areas of the Namib Desert particularly between Gobabeb and Lüderitz. Of these, northwestern Namibia is likely to host as-yet undiscovered diversity of Acanthaceae whereas the lowland Namib, with its much more succulent flora having affinities to the Succulent Karoo of South Africa, is likely to be species poor for Acanthaceae (E. A. Manzitto-Tripp & K. Dexter, pers. obs.). This is reflected in the low number of species of Barleria and other Acanthaceae taxa in the Sperrgebiet diamond mining restriction zone, recently declared the Tsau Khaeb National Park in the southwest of Namibia, which has received better botanical coverage than the areas north of Lüderitz (F. M. Chase, pers. obs.).
Despite these knowledge gaps, some clear distributional patterns are discernible. Of particular note, the western portions of Namibia, and in particular the Kaokoveld and the higher elevation areas of the Namib Desert, are clearly more rich in Barleria and other Acanthaceae than are the eastern Kalahari Desert and fringes. This, at least in part, reflects the high landscape and geological complexity and relatively high soil fertility in the west, all of which are favourable to Acanthaceae diversity in general (Tripp & Luján 2018). This is in contrast to the relatively uncomplex, plain-like landscape and the deep, leached sands (arenosols) with low nutrient content in the Kalahari Basin (Mendelsohn et al. 2002). The Namibian Kaokoveld (c in Fig. 14C) is a complex arid region with much variation in relief and geology resulting in varied micro-habitats and xeric vegetation types. This area holds several endemic or range-restricted species of Barleria, including B. damarensis, B. grootbergensis and B. meeuseana P.G.Mey. In addition, as in the Lubango Highlands, this region has high richness across infrageneric taxa of Barleria (Fig. 16). The Kaokoveld is well-documented as a centre of plant diversity and endemism (Hilton-Taylor 1994;Maggs et al. 1998;van Wyk & Smith 2001;Craven 2009), with high numbers of endemics noted in the Ac anthac eae as w ell a s i n Ap o cy nac eae, Burseraceae (with a major radiation of Commiphora Jacq.), Capparaceae, Cucurbitaceae, Fabaceae, Poaceae and Vitaceae (van Wyk & Smith 2001). Brandberg in Erongo Region, the highest mountain in Namibia, is included as a southern outlier of the Kaokoveld Centre of Endemism by van Wyk & Smith (2001). It is known for its point-endemism, including in Acanthaceae the striking Ruellia brandbergensis Kers and Peristrophe namibiensis Balkwill subsp. brandbergensis Balkwill (Balkwill et al. 1988;Tripp & Dexter 2012). Whilst there Fig. 16. Distribution of infrageneric taxa of Barleria in Angola and Namibia; taxon richness per half-degree-square. A subg. Barleria; B -D subg. Prionitis; B sect. Prionitis; C sect. Somalia; D sect. Stellatohirta. are no endemics of Barleria on Brandberg itself, the mountains in the vicinity, particularly to the west (d in Fig. 14C), are relatively species rich and this is a key area for two range-restricted species, B. merxmuelleri P. G.Mey. and B. solitaria P.G.Mey., both of which can be considered southern Kaokoveld endemics.
Elsewhere in Namibia, the area in the vicinity of Outjo and Otjiwarongo on the border of Kunene and Otjozondjupa Regions (e on Fig. 14C) is rich in species of Barleria. This is a particularly wellbotanised area, easily accessible via main transport routes, and so may be affected by collecting bias. Regardless, this area does include some rangerestricted species of Barleria including the apparently endemic B. violacea from Outjo, and B. jubata S.Moore, which is restricted to the sandstones of Waterberg and neighbouring hills.
In southern Namibia, the Gariep Centre of Plant Endemism, which is shared with the Northern Cape of South Africa and which includes the famous Richtersveld (van Wyk & Smith 2001), is not as species rich for Barleria as is the Kaokoveld, but is notable for containing several endemics, including B. craveniae I. Darbysh. and B. papillosa T.Anderson, the latter of which is globally threatened (Fig. 15). The Gariep Centre, a part of the Succulent Karoo, is, like the Kaokoveld, notable for its landscape and geological complexity. Its endemic flora contains a high succulent component, most notably in the Aizoaceae: Mesembryanthemoideae, although nonsucculent endemics are also plentiful (van Wyk & Smith 2001). The mountainous parts of this Centre still have much to discover; for example an as yet undescribed species of Petalidium is known from this region and the rare and striking succulent subshrub Sarcocaulon herrei L.Bolus (= Monsonia herrei (L.Bolus) F.Albers; Geraniaceae) was recently recorded for the first time in Namibia from here (Nanyeni & Nzuma 2018). Higher species richness of Barleria per half-degree-square is noted further east in southeast Karas Region (f in Fig. 14C) in the Karas Dwarf Shrubland vegetation type of Mendelsohn et al. (2002), but this area does not hold any narrow-endemic species in the genus. This area is under-collected but is known to have an interesting flora, with much still to discover. For example, the striking geophyte Eriospermum paradoxum (Jacq.) Ker Gawl. (Asparagaceae) has recently been found in Namibia for the first time in the Warmbad area, a proposed Important Plant Area (F. M. Chase, pers. obs).

Distribution of infraspecific taxa of Barleria in Angola and Namibia
Distribution patterns vary significantly between the monophyletic subgenera and sections of Barleria (Fig. 16). Subg. Barleria is richest in the deserts and xeric shrublands of the Namib Desert and Kaokoveld Centre of Endemism and accounts for most of the endemism in Namibia (Fig. 16A). Sect. Somalia, on the other hand, becomes more diverse and abundant in the fire-prone miombo woodlands and savannas rich in geoxylic suffrutices in Western Angola and northeastern Namibia (Fig. 16C), the southwestern portion of the Zambesian Centre of Endemism. This is also reflected by differences in growth habit: the majority of species in subg. Barleria are shrublets whilst many of the species in sect. Somalia are suffruticose with a woody base and rootstock and with annual aboveground growth. It is notable, however, that species richness in both these sections peaks in the Lubango Highlands of Angola. Clearly, this area must be considered a conservation priority for Barleria and, given that the natural habitats of this area are highly threatened by human activities, the Lubango Highlands must be considered a high priority for formal protection and biodiversity management.
grateful to all our fieldwork collaborators. In particular, Kyle Dexter (University of Edinburgh) has been a key collaborator on many of the fieldtrips through Namibia and Angola and is thanked for his extensive contributions. Leevi Nanyeni of NBRI is thanked for his excellent contribution to the Namibian fieldwork; Leevi was also a great help with addressing various queries regarding specimens in the WIND herbarium. We would also like to thank the following curators and research staff for providing access to the herbarium collections of Barleria at their institutions: Robert Vogt (B), Ranee Prakash and Jacek Wajer (BM) We thank David Goyder of the Royal Botanic Gardens, Kew for seeking out Acanthaceae during his various expeditions to Angola over the past few years and for his helpful advice on the phytogeography and botanical history of that fascinating country. Patricia Craven has helpfully provided information on species distributions and collections of Barleria in Namibia. Equally, Willem Froneman of the South African National Biodiversity Institute (SANBI) has provided useful information on and photographs of the southern African species of Barleria. We are again highly grateful to Andrew Brown for the excellent illustrations of the newly described species. Finally, we thank Pedro Beja, Barbara Ditsch, Francisco Gonçalves, David Goyder, Fernanda Lages, Teresa Leyens and Warren McCleland for granting permission to use their photographs of Barleria species and Dr Stefan Dressler of the Forschungsinstitut Senckenberg for facilitating access to images of Barleria via the African Plantsa Photo Guide website.
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