Six new species of coffee (Coffea) from northern Madagascar

Six new species of Coffea are described as new to science: Coffea callmanderi, C. darainensis, C. kalobinonensis, C. microdubardii, C. pustulata and C. rupicola. All six species are endemic to northern Madagascar; four species are narrowly endemic to specific forest areas. Associated information, including distribution maps, conservation assessments, phenology and taxonomic notes are provided, and two species are illustrated with line drawings.


Introduction
Madagascar is home to 59 species of Coffea L. (Davis et al. 2006;Davis & Rakotonasolo 2008;Davis et al. 2010), which is nearly half of the 124 known to exist in the world (Davis et al. 2019). The 65 other Coffea species are found in Africa (48 species), the Comoros islands (one species), Mascarene Islands (three species; although a fourth (C. bernardiniana J.-F.Leroy) is sometimes recognised), Indian subcontinent and Sri Lanka (six species), south tropical Asia (two species), south-eastern Asia (four species) and Australasia (one species) (Davis 2011;Davis et al. 2011Davis et al. , 2019. Starting in 2003, a series of field expeditions were conducted to explore the flora and vegetation in a long-neglected region of low to high elevation humid forest in northern Madagascar (Callmander et al. 2018) and the north-western Daraina area, which is located at the crossroads of four main phytogeographic units and possesses a variety of forest types (Gautier et al. 2006;Nusbaumer et al. 2010). Despite the bewildering diversity already enumerated for Madagascan Coffea, examination of field collections from the above-mentioned fieldwork and further field study in northern Madagascar revealed that it was necessary to describe six new species of Coffea: C. callmanderi A.P.Davis & Rakotonas., C. darainensis A.P.Davis & Rakotonas., C. kalobinonensis A.P. Davis & Rakotonas., C. microdubardii A.P.Davis & Rakotonas., C. pustulata A.P. Davis & Rakotonas., and C. rupicola A. P.Davis & Rakotonas. These new species are described here. Associated information, including distribution maps and provisional conservation assessments are also provided, and two species are illustrated with line drawings. These new species join others that have been recently described on the basis of the material collected from the mountainous regions of northern Madagascar (e.g. Callmander et al. 2008Callmander et al. , 2009Callmander et al. , 2012Callmander et al. , 2020Randrianasolo & Lowry 2009;Walhert 2016) and the Daraina area (Phillipson et al. 2018).
Three of the new species, Coffea darainensis, C. microdubardii and C. rupicola, are restricted to the protected area of Loky Manambato in the Daraina area, and a further two, C. callmanderi and C. kalobinonensis, are found only in the protected area of Galoko-Kalobinono. Coffea pustulata is also found in the Daraina area, but is not restricted to this locality, and occurs in other humid, evergreen forests of northern Madagascar. Loky Manambato represents a dozen forested massifs in central-northern Madagascar  and Galoko-Kalobinono two large massifs (Tahinarivony & Callmander 2018) in the southern part of the narrow mountain Galoko chain running in a more or less north-south direction, c. 35 km long, close to the town of Ambanja (Moat & Smith 2007). Until recently the forests of Loky Manambato and Galoko-Kalobinono were almost unknown botanically. The intense inventories of the last two decades have highlighted these two forest areas as places of high-level regional endemism (Callmander et al. 2008(Callmander et al. , 2009(Callmander et al. , 2012(Callmander et al. , 2020Gautier et al. 2006;Nusbaumer et al. 2010;Phillipson et al. 2018;Randrianasolo & Lowry 2009;Ranirison et al. 2018;Schatz & Lowry 2020;Tahinarivony & Callmander 2018;Wahlert 2016). These data and other information has led to Loky Manambato and Galoko-K alobinono b eing encompassed i n Madagascar's protected area network (Goodman et al. 2018). The description of the six new species of Coffea described here, further illustrate the value of targeted botanical exploration and the biological richness of these areas.
The naming of the six new species described here brings the total number of Coffea species in Madagascar to 65, and the number of coffee species to a global total of 130.

Material and Methods
Herbarium material of Madagascan Coffea species was consulted in person, or from loans, held in the collections of the following institutes: G, K, MO, P, TAN (abbreviations after Holmgren et al. 1990;Thiers 2020). All specimens cited have been seen by the authors (type specimens indicated with an exclamation mark).
Dedicated fieldwork for Coffea was undertaken in Makira, near Maroantsetra (Province Toamasina; Region Analanjirofo; District Maroantsetra) and Kalobinono in the Galoka mountain range, near Ambanja (Province Antsiranana; Region Diana; District Ambanja) by the authors in 2007 and 2009, respectively. The measurements, colours and other details given in the descriptions are based mostly on herbarium specimens, but also from living plants and data derived from field notes. Further information on Coffea morphology is provided in Davis et al. (2005Davis et al. ( , 2006Davis et al. ( , 2007Davis et al. ( , 2011, Davis & Rakotonasolo (2008), and Maurin et al. (2007).

Coffea microdubardii
RECOGNITION. Coffea microdubardii resembles C. dubardii Jum., due to the presence of numerous prominent tertiary veins that run parallel to the secondary veins, and the general morphology of the inflorescence and the flowers. Overall, microdubardii represents a much smaller version of C. dubardii, but with many differences in the number of features and also nonquantitative differences. The main differences between these species are as follows (dimensions and character states for C. dubardii given in square brackets): treelet 2.5 -2.8 m high [vs treelet or small tree, (1 -) 1.7 -6 (-7) m high]; petiole 0.2 -0.5 cm long, puberulous [vs (0.5 -) 0.8 -1.1 cm long, glabrous]; leaf blade (2.2 -) 3 -5.2 × (1 -) 1.3 -3.3 cm [vs (5 -) 7 -10.5 (-12.5) × (2.2 -) 3 -5.5 (-6.5) cm]; secondary veins (5 -) 6 -8 pairs [vs (6 -) 8 - 12 (-14) pairs]; leaf domatia sparsely to densely puberulous (hairs 0.1 -0.2 mm long) [vs distinctly pubescent (hairs many, 0.2 -0.4 mm long)]; inflorescences restricted to the upper nodes of the shoot, 1 per leaf axil, each inflorescence 3 -6-flowered, 7 -10 mm long [vs inflorescences in several nodes of the shoot, 1 or 2 (-3) per leaf axil, each inflorescence (3 -) 4 -8 (-10)-flowered, 5 -12 (-15) mm long]; calyx (incl. hypanthium) 1.5 -1.7 × 1 mm [vs 1.8 -2.5 × 1.8 -2.3 mm]; corolla 9 -13 × 9 -16.8 mm [vs (10 -) 14 -19 × 10 -17.1 mm]; corolla tube ± the same length as the corolla lobes, 6 -7 mm long [vs corolla tube distinctly longer than corolla lobes, (6 -)  2012). EN B1ab(iii)+2ab(iii). B1 extent of occurrence (EOO) estimated to be less than 5000 km 2 (c. 21 km 2 for C. microdubardii); aseverely fragmented known to exist at three locations; and b (iii)continuing decline projected, in area, extent and/or quality of habitat. B2 area of occupancy (AOO) estimated to be less than 500 km 2 (16 km 2 for C. microdubardii, at a cell width of 2 km; 4 km 2 at a cell width of 1 km); aseverely fragmented (see above); and b and b (iii)continuing decline projected, in area, extent and/or quality of habitat. The EOO and AOO both fall well within the limits for the EN category and almost within the Critically Endangered (CR) category. Further fieldwork is required to provide more precise distribution metrics and threat information for this species. The distribution of C. microdubardii includes populations in the Loky Manambato Protected Area in the forests of Binara, Antsahabe and Ankaramy. PHENOLOGY. Imperfectly known -flowering from December, and probably November; fruiting from late October to May. ETYMOLOGY. Coffea microdubardii is so named due to resembling a much smaller version of C. dubardii. NOTES. Coffea microdubardii looks like a much smaller version of C. dubardii, a quite frequently encountered Coffea species of northern Madagascar. These two species are easy to separate morphologically. The size of the leaves and number of secondary veins offers an easy means of recognition: leaves 3 -5.2 cm long and with 6 -8 pairs of secondary veins in C. microdubardii, versus mostly 7 -10.5 cm long and with 8 -12 pairs of secondary veins in C. dubardii. In addition, C. microdubardii does not have the drought resilience adaptations that are present in C. dubardii, including 'resting' shoot-buds and partial deciduousness, i.e. leaves relaxing due to movement in the petiole, or sometimes falling from the plant, during times of heat/drought stress.

Coffea callmanderi
RECOGNITION. Coffea callmanderi is somewhat similar to C. richardii J.-F.Leroy as both have large (usually more than 15 cm long and 6 cm wide) coriaceous leaves, with usually more than ten prominent secondary veins. These species are, however, easily set apart, on the basis of the following characters (those for C. richardii are given in square brackets): leaves elliptic to obovate, or elliptic-ovate, (9.5 -) 15.8 -17.2 × (4.8 -) 5.8 -8.3 cm [vs broadly elliptic to narrowly elliptic, oval to oval-ovate, or rarely oval-obovate, 17 -23. ). CR B2ab(iii). B2 area of occupancy (AOO) estimated to be less than 10 km 2 (8 km 2 at a cell width of 2 km; 2 km 2 , at cell width 1 km); aknown to exist at only a single location; and b (iii)continuing decline, observed, and projected, in area, extent and/or quality of habitat. The AOO falls well within the limits for the CR category; even if several other subpopulations are found within the location and available forest area (which extends someway to the north), the AOO would still fall within the CR category. We designated a cell width of 1 km on the basis that the forest fragments in which this species occurs are less than 1 km wide. At the only known location for this species, there is an ongoing and drastic reduction of forest cover (which this species requires) due to agricultural expansion and human habitation (new settlements). The known distribution range of Coffea callmanderi falls within the Galoko-Kalobinono Protected Area. PHENOLOGY. Imperfectly known -flowering in November; probably fruiting from December to February, and possibly March. ETYMOLOGY. Coffea callmanderi is named after Martin W. Callmander, who discovered this species, coorganised the first collecting mission to the Galoko-Kalobinono mountainous area, and undertook considerable exploratory fieldwork in northern Madagascar. NOTES. Coffea callmanderi is an intriguing species as it does not resemble any other species from northern Madagascar, but rather the large-leaved species from lowland eastern Madagascar, C. richardii J.-F.Leroy and C. farafanganensis J.-F.Leroy, particularly the former species. Despite the flowers being largely unknown and fruits not known, C. callmanderi is easily set apart from C. richardii on the basis of leaf and flower characteristics (see Recognition). Small tree, 4 -6 m high, dbh c. 6 cm. Bark browngrey, mottled, slightly rough. Branches 8 -10 mm in diam., ± smooth, dark brown. Branchlets ± terete, 3 -4 mm in diam., ± smooth, dark brown, puberulous (hairs c. 0.05 mm long) on young shoots. Stipules caducous, depressed ovate or depressed ovate-truncate, 1.3 -1.7 × 1.4 -1.6 mm, subcoriaceous, puberulous like the young shoots; margin ciliate (hairs c. 0.1 mm long); apex broadly acute to very broadly acute. Leaves: petiole 0.7 -1.7 cm long, glabrous; lamina elliptic-obovate, or ± obovate, or elliptic to broadly elliptic, (5.5 -) 8 -10 × (2.2 -) 2.9 -4.6 cm, subcoriaceous; base narrowly cuneate, decurrent; margins subrevolute to flat; apex obtuse to broadly acute, very abruptly caudate, cauda 0.2 -0.4 cm long; abaxial surface: secondary veins prominent, 6 -8 pairs, with prominent intermediates (intersecondaies), ascending at an angle of c. 45°, tertiary venation rather prominent, ± reticulate; higher order venation manifest to obscure, ramified; texture smooth; domatia prominent, located in the axils of the secondary veins, against the midrib, orifice, c. 0.4 mm in diam., surrounding leaf tissue slightly swollen, glabrous or sparsely covered in small hairs (c. 0.05 mm long); adaxial surface: venation prominent; domatia obscure to manifest. Inflorescences interfoliar, 1 per leaf axil, each inflorescence 3 to 5-flowered, 8 -9.8 mm long, shortly branched (1 or 2 orders of branching), mostly exudate free; inflorescence axis (part bearing calyculi) 3.8 -6.4 mm long. Calyculi 3, shortly stalked to stalked (stalks 0.4 -0.6 mm long); glabrous, margins ciliate (hairs c. 0.mm long); basal (1st)  RECOGNITION. Coffea kalobinonensis is similar to C. coursiana J.-F.Leroy, a species from the humid, evergreen forests of Eastern Madagascar, due to the overall appearance of leaves and by having multifl owered inflorescences. Even though C. kalobinonensis is imperfectly known, these species are, however, easily set apart, on the basis of the following characters (those for C. coursiana are given in square brackets): petioles 0.7 -1.7 cm long [vs 0.2 -0.9 cm long], lamina (5.5 -) 8 -10 × (2.2 -) 2.9 -4.6 cm [vs 3.5 -7 (-8.4) × 1.8 -3. HABITAT & ECOLOGY. Humid, evergreen forest within the Sambirano Region; on ridges; on (Isalo) sandstone; elevation 550 -950 m above sea level. CONSERVATION ASSESSMENT. Provisionally assessed as Critically Endangered (IUCN 2012). CR B1ab(iii) +2ab(iii). B1extent of occurrence (EOO) estimated to be less than 100 km 2 (0.7 km 2 for Coffea kalobinonensis); aknown to exist at only a single location (one location for C. kalobinonensis); and b (iii)continuing decline projected, in area, extent and/or quality of habitat. B2 area of occupancy (AOO) estimated to be less than 10 km 2 (8 km 2 for C. kalobinonensis, at a cell width of 2 km; 3 km 2 at a cell width of 1 km); aknown to exist at only a single location; and b (iii)continuing decline, observed, and projected, in area, extent and/or quality of habitat. EOO and AOO fall well within the limits for the CR category; even if other subpopulations are found within the known location or surrounding areas, the limits of this category are unlikely to be breached. At the only known location for this species, there is an ongoing and drastic reduction of forest cover (which this species requires) due to agricultural expansion and human habitation (new settlements). The known distribution range of C. kalobinonensis falls within the Galoko-Kalobinono Protected Area. PHENOLOGY. Imperfectly knownprobably flowering from November to December; fruiting from late December, probably until March. ETYMOLOGY. Coffea kalobinonensis is named after the Kalobinono Mountain in north-western Madagascar, a location with a high number of endemics and considerable biodiversity. NOTES. Coffea kalobinonensis resembles a larger variant of C. coursiana, but these species are easily separated on the basis of several morphological differences (see Recognition). Coffea kalobinonensis is restricted to the Kalabinono mountain area of north-western Madagascar (Sambirano region), at 550 -950 m, whereas C. coursiana occurs in the humid, evergreen forests of Eastern Madagascar (usually at 400 -500 m). MO, P, TAN and TEF for the loan or use of material for this study; Martin Callmander and Louis Nusbaumer for providing assistance with fieldwork logistics, and for various resources and guidance used in the production of this contribution; Louis Nusbaumer and Patrick Ranirison for the use of field images; and Lucy T. Smith for providing the line drawings of Coffea.

Coffea kalobinonensis
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