Kew Bulletin

, 64:513

Aloysia axillaris (Verbenaceae), a new species, with notes on the genus in Bolivia

Authors

    • Department of Plant SciencesUniversity of Oxford
    • Honorary Research Associate
Article

DOI: 10.1007/s12225-009-9131-5

Cite this article as:
Wood, J.R.I. Kew Bull (2009) 64: 513. doi:10.1007/s12225-009-9131-5

Summary

Taxonomic and ecological notes on all species of Aloysia Palau occurring in Bolivia are provided together with a key to the species. Variation within several species is discussed and questions are raised about the status of many varieties recognised by earlier botanists. A. arcuifolia Nesom and A. herrerae Moldenke are treated as synonyms of A. fiebrigii (Hayek) Moldenke, A. beckii Moldenke and A. mizquensis Ravenna are treated as synonyms of A. gratissima (Gillies & Hook.) Tronc., A. boliviensis Moldenke, A. depressa Ravenna and A. peruviana Turcz. are treated as synonyms of a very variable A. scorodonoides (Kunth) Cham. ex Moldenke which intergrades with A. virgata (Ruiz & Pav.) Juss. ex Moldenke. A table of differences is provided to help distinguish these two ill-defined species. A. axillaris J. R. I. Wood, a Bolivian endemic is described as new, its solitary axillary flowers extending the definition of Aloysia to include species with this kind of inflorescence. The new species is illustrated.

Key words

Boliviadistributiontaxonomyvariation

Aloysia Palau is a small genus of around 20 neotropical shrubs closely related to Lantana L. and Lippia L. from which it is distinguished by the calyx which is distinctly 4-toothed. The taxonomy of all three genera is difficult as many species show clinal change over their range with much local variation and are ill-defined with sometimes overlapping characters. Additionally, the taxonomy of Aloysia has been complicated by the works of Moldenke, Ravenna and others, who, despite having little knowledge of the plants in the field, have published numerous new species in isolated papers making little reference to and no comparison with previously published related species. Many of their species are based on single collections and their publications make no reference to the known variability of most species in the genus. Macbride’s comments (1960: 610) describe well the frustration of trying to make systematic sense of the numerous species described by Moldenke and elaborate on the problems mentioned above. In order to try and avoid some of these pitfalls, this account is limited to the species of Aloysia from Bolivia, where the author has a good knowledge of the species and their variation in the field. Although taxa from other South American countries have been examined I have generally avoided taxonomic judgements on plants whose wider variation is outside my field knowledge. However, I would like to indicate my appreciation of the work of Troncoso (1962) and Botta (1979, 1993) in Argentina and concur with the broad species concept they have adopted even when I occasionally disagree with some details of their accounts.

Several kinds of variation can be noted in Aloysia. Populations of several species show slight character changes over distance so that plants from one part of the range of a particular species differ somewhat from those in another area. Variation of this kind is commented on where appropriate below but the lack of ecological data in many Argentinean publications and herbarium collections has made generalisation somewhat difficult. Formal recognition of varieties to account for this kind of clinal variation is often unsatisfactory as taxa can only be defined arbitrarily. I have, therefore, treated several hitherto recognised varieties as synonyms of recognised species. However, I have maintained var. parvifolia Moldenke of A. scorodonoides (Kunth) Cham. ex Moldenke as the small leaves differ strikingly from the type variety and it is restricted to unusually high altitudes in southern Peru and northern Bolivia. Nevertheless intermediates between var. parvifolia and the type variety occur in the same general area, albeit generally at lower altitudes, so there is no very satisfactory clear-cut distinction even for this variety.

There is also some introgression between species, notably between Aloysia virgata (Ruiz & Pav.) Juss. ex Moldenke and A. scorodonoides but also, outside Bolivia, between the former and A. gratissima (Gillies & Hook.) Tronc. While it is clearly unsatisfactory to have ill-defined species of this sort, the phenomenon is not unique to Aloysia, occurring in the apparently related Lantana, for example. Hybridisation might be suggested as an explanation for some of this variability but, while this certainly cannot be ruled out, I have seen nothing to support this idea. Mixed populations are rare and I have no evidence either from my own observations or from notes on herbarium specimens that intermediates occur when two species grow together. I have maintained the name var. mathewsii Moldenke of A. scorodonoides for forms intermediate between A. scorodonoides and A. virgata as a pragmatic solution to the problem of naming intermediates between these species. This has the advantage of using an existing name for an otherwise unnamable entity without implying that it is a hybrid. These intermediate forms are uncommon.

A third type of variation consists of the occasional, apparently random occurrence of a distinct form. One example is the type specimen of Aloysia boliviensis Moldenke, which seems to be some kind of freak in which the internodes are much reduced so the leaves appear to be arranged in verticels, rather than opposite pairs. Another good example is the occurrence of serrate-leaved forms of normally entire-leaved species. A serrate-leaved form of A. citrodora Palau was described as A. sleumeri by Moldenke (1964) and treated by Botta (1979) as synonymous with the former. Other examples include var. schulziana (Moldenke) Botta of A. gratissima and var. argutidentata Moldenke of A. virgata. Although I doubt the utility of describing these as varieties, I have not formally treated them as synonyms as they are based on types from outside Bolivia.

All specimens cited have been seen unless indicated otherwise.

AloysiaPalau (1784: 767). Type species: A. citrodora Palau.

Small unarmed shrubs. Leaves opposite or whorled, rarely alternate; toothed or entire, usually strongly aromatic. Flowers in racemes, very rarely solitary in the leaf axils; calyx tubular. 4-toothed, the teeth triangular to subulate; corolla hypercratiform, tube short, pubescent inside, lobes 4; stamens 4, inserted in the upper part of the corolla tube, anthers bithecate; ovary bilocular; stigma apical, slightly lateral. Fruit separating into 2 dry mericarps. Widespread in the drier parts of the neotropics from the southern United States to Argentina and Chile. Number of species variously estimated up to 40 but probably about half this number.

In Bolivia Aloysia is abundant in the drier inter-Andean valleys, where several species are important constituents of dry bushland or of the understorey of open deciduous dry woodland. Most species are pleasantly aromatic and at least two, A. polystachya and A. citrodora, are cultivated. The latter, in particular, is commonly grown in gardens for its lemon-scented leaves which are used in the preparation of aromatic teas.

Key to species ofAloysiaknown from Bolivia

  • 1. Inflorescence ± terminal on the branches; leaves mostly in whorls of 3, occasionally some in opposite pairs . . . . . . . 2

  • Inflorescence strictly axillary; leaves in opposite pairs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

  • 2. Leaves linear-lanceolate, 1.8 – 3 × 0.2 – 0.5 cm, entire; spikes 1 per leaf axil, short and often indistinctly spicate, 1 – 3 cm long . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3. A. fiebrigii

  • Leaves lanceolate to ovate-lanceolate, 3.5 – 7.5 × 1 – 1.5 cm, entire or (rarely) serrate; spikes 1 – several per leaf axil, clearly spicate, mostly 3 – 6 cm long . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2. A. citrodora

  • 3. Leaves alternate; flowers in short, subsessile, subglobose, contracted racemes . . . . . . . . . . . . . . . 1. A. polystachya

  • Leaves opposite; flowers in pedunculate, elongate racemes (rarely reduced and subglobose) or solitary in the leaf axils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

  • 4. Leaves entire or, rarely, irregularly dentate or serrate, oblanceolate, attenuate at base . . . . . . . . . 4. A. gratissima

  • Leaves crenate or serrate, ovate to elliptic or suborbicular, usually abruptly narrowed at the base . . . . . . . . . . . 5

  • 5. Some or all flowers solitary in the leaf axils, occasionally also some in racemes; leaves all < 1.5 cm long . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7. A. axillaris

  • Flowers all in racemes; some leaves > 2 cm long . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

  • 6. Leaves 1.5 – 4.5 (– 6) × 1.5 – 3 (– 3.5) cm, white-canescent beneath, apex obtuse, margin regularly crenate; racemes ± straight, solitary in each leaf axil, very dense with flowers imbricate, so the bases are hidden . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6. A. scorodonoides

  • Leaves 4 – 9 × 1.5 – 6 cm, concolorous or slightly paler beneath, very variable in shape but often acute at the apex and the margin irregularly toothed; racemes flexuose, often paired in each leaf axil, relatively lax with flower bases easily visible . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5. A. virgata

1. Aloysia polystachya (Griseb.) Moldenke (1940: 380). Type: Argentina, Lorentz s.n. (holotype GOET; isotype SI).

Lippia polystachya Griseb. (1874: 194).

Aromatic shrub characterised by its alternate, entire, prominently-nerved, lanceolate, strigose leaves. Inflorescence of subsessile, dense, contracted, spiciform, axillary racemes, usually 0.5 – 1.2 cm long and wide.

Distribution & Habitat. Native to the western chaco of Argentina, this might be expected to occur as a native plant in southern Bolivia. However, apart from a collection (Krapovickas & Schinini 31277) cited by Botta (1979: 107) without comment, there is no evidence of its status in Bolivia apart from the following record as a cultivated plant.

Specimen Examined. Bolivia. Chiquitos, cultivated in Chochis village [18°08′S, 60°02′W], 350 m, 20 Oct. 2003, J. R. I. Wood 19773 (K, LPB, USZ).

2. Aloysia citrodoraPalau (1784: 768). Type: Unnumbered illustration by B. Salvador y Caruna in Palau (1784), lectotype selected by Armada & Barra (1992: 89).

Lippia citriodora (Palau) Kunth (1818: 269).

Verbena triphylla L’Hér. (1786: 21). Type: C. L. L’Héritier de Brutelle s.n. (P, n.v.), a cultivated plant grown from seed sent by Commerson from Montevideo, lectotype selected by Moldenke & Moldenke (1983: 232).

Lippia triphylla (L’Hér.) Kuntze (1898: 253).

Aloysia triphylla (L’Hér.) Britton (1925: 140).

Aromatic shrub smelling strongly of lemon. Leaves in whorls of 3, occasionally in opposite pairs, entire (rarely, outside Bolivia, serrate), lanceolate, 3.5 – 7.5 × 1 – 1.5 cm. glabrous or nearly so. Inflorescence of 1 – several spike-like racemes from each leaf-like bract, each up to 6 cm in length, thus often forming a compound, lax inflorescence.

Distribution & Habitat. Apparently native in northern Argentina (Salta, Jujuy, La Rioja and Catamarca) and southern Bolivia (Chuquisaca, Cochabamba, Potosi and Tarija), where it is a local, but sometimes abundant component of arid bushland in the dry inter-Andean valleys between 2300 – 3250 m. Also widely cultivated in Bolivia and throughout tropical and subtropical America for use as a herbal tea and in traditional medicine.

Specimens Examined. Bolivia (all records of apparently native populations). Chuquisaca: Oropeza, 1 km above Yotala, 2600 m, 30 Oct. 1993, J. R. I. Wood 7600 (K, LPB); 1 km below La Glorieta between Sucre and Yotala, 2600 m, 21 Jan. 1995, J. R. I. Wood 9181 (K, LPB). Zudañez, 4 – 5 km above Presto along road to Tarabuco [18°59.38′S, 64°56.31′W], 2521 m, 4 Feb. 2007, J. R. I. Wood, H. Huaylla & J. Gutierrez 22649 (HSB, K, LPB). Cochabamba: Carrasco, c. 1 km N of Hoyadas on road from Aiquile to Totora [17°31.12′S, 65°06′W], 2500 m, 1 Feb. 2005, J. R. I. Wood 21568 (BOLV, K, LPB). Mizque, camino Molineros-Botijas, 2700 m, 24 Jan. 1994, López & Saravia 156 (BOLV). Quillacollo, Termales La Cascada [17°37.27′S, 66°21.82′W], 2542 m, 11 March 2003, M. Mercado 2590 (BOLV, LPB).Tapacari, between Parotani and Llavini, 3000 m, 11 Feb. 2005, J. R. I. Wood, M. Atahuachi & T. Ortuño 21602 (BOLV, K, LPB). Potosi: Bustillos, 41 km from Uncia towards Rio Colorado, Pocoata, 3300 m, S. G. Beck 6162 (LPB). Chayanta, Rio Colorado, 3240 m, 14 March 1993, G. Torrico & C. Peca 141 (BOLV). Saavedra, Alto Retiro, 80 km from Potosi towards Sucre, 30 March 1993, E. Torrico, S. G. Beck & C. Peca 260. Tarija: Mendez, Río Pilaya, 2350 m, 4 Feb. 1982, Gerold 161 (LPB). Bolivia (Records of cultivated plants). Cochabamba: Capinota, Apillapampa [17°51′05″S, 66°15′04″W], 3260 m, E. Thomas 496 (BOLV). Cercado, in hotel garden, 2500 m, 12 Feb. 1987, M. Nee & J. Solomon 34110 (LPB). Quillacollo, Hosteria Claudia [17°23′S, 66°08′W], M. Saldias 265 (USZ). La Paz: Murillo, La Paz city, S. G. Beck 4304 (LPB); Calacota [16°31′S, 68°05′W], 16 Nov. 1986, J. Solomon 15755 (LPB). Santa Cruz: Vallegrande town [18°29′S, 64°06′W], 2040 m, 4 Jan. 1989, I. G. Vargas 17 (USZ).

Notes. The epithet citrodora is as spelt by the original author rather than the more common, erroneous and less logical citriodora.

A serrate-leaved form from Argentina was described by Moldenke (1964: 170) as a “distinctive species” under the name Aloysia sleumeri. Botta (1979: 102) reduced this to synonomy with A. citrodora after finding entire and serrate-leaved plants growing together in the same area. Serrate-leaved plants have never been collected in Bolivia.

3. Aloysia fiebrigii (Hayek) Moldenke (1937: 15). Type: Bolivia, Tarija, Fiebrig 3036 (lectotype K, selected here).

Lippia fiebrigii Hayek (1908: 165).

Aloysia herrerae Moldenke (1941: 10). Type: Peru, Urubamba, Herrera 1534 (holotype F; possible isotype K), synon. nov.

Aloysia arcuifolia Nesom (1991: 145). Type: Bolivia, Potosí, R. Ehrich 339 (holotype TEX; isotype LPB), synon. nov.

Similar to Aloysia citrodora in general habit but distinguished by its smaller, linear-lanceolate leaves, 1.8 – 3 × 0.2 – 0.5 cm. The inflorescence is compact with short (1 – 3 cm long) racemes, arising singly from each leaf-like bract; the racemes are indistinctly spicate.

Distribution & Habitat. A rare but probably overlooked species of scattered localities in very arid subpuna scrub from 2900 – 3500 m in northern Argentina, southern Bolivia, and southern Peru.

Specimens Examined. Bolivia. Chuquisaca: Zudañez, at top of descent from Candelaria to Icla, 2900 m, 13 March 1999, J. R. I. Wood & M. Serrano 14658 (HSB, K, LPB). Potosi: Valle de Palqui, 3500 m, 7 Feb. 1987, R. Ehrich 339 (LPB). Nor Chichas, sin data, 3300 m, G. Torrico & C. Peca 390 (BOLV, LPB). Sud Chichas, road from Tupiza to El Sillar via Quebrada Palala, 3200 m, 29 March 1997, J. R. I. Wood 11960 (K, LPB). Tarija: Paisho near Tarija, 3000 m, 4 Feb. 1904, Fiebrig 3036 (K).

Notes. Von Hayek cited two syntypes, Fiebrig 3036 from Tarija and Weberbauer 4910 from Urubamba in Peru. The original specimens which von Hayek used to prepare his description were apparently destroyed at Berlin in 1943. As lectotype I have selected the Fiebrig collection at K as the specific epithet is linked to this collector. There are likely to be isolectotypes in various European herbaria. The type of Aloysia herrerae was also collected at Urubamba. There is a possible isotype at Kew with the same collection details but numbered 15351, not 1534 and mixed with A. spatulata Hayek, the two presumably having been mounted together in error. In fact, A. fiebrigii has been collected several times in the Urubamba region of Peru, from where I have also seen E. W. Davis et al. 1757 ( K).

Aloysia fiebrigii and A. citrodora, are clearly a pair of related species. Both commonly have leaves in whorls of 3 – 4 and an inflorescence ± terminal on the branches rather than clearly axillary as in other species. A strong lemon scent is characteristic of both. All specimens I have seen can be separated without difficulty by the characters given in the key and I am unaware of any intermediates, but it is possible that A. fiebrigii may eventually prove to be no more than a reduced form of A. citrodora adapted to very arid conditions. In any case the combined native distribution of the two species shows a striking parallel to that of Salvia cuspidata Ruiz & Pav., sensu Wood (2007) with disjunct populations on the western Andean slopes of Peru, absence or near absence from the La Paz area, extensive populations in the Cochabamba and Sucre areas, and a wide distribution further south in the subpuna areas of southern Bolivia and north-western Argentina.

4. Aloysia gratissima (Gillies & Hook.) Tronc. (1962: 547). Type: Argentina, Mendoza, Gillies s.n. (holotype K, sheet with Hooker’s drawing; isotype OXF).

Verbena gratissima Gillies & Hook. in Hook. (1830: 160).

Aloysia lycioides Cham. (1832: 237). Type: Southern Brazil, Sellow s.n. (holotype LE, n.v.).

Lippia lycioides (Cham.) Steud. (1841: 54).

Aloysia beckii Moldenke (1982: 18). Type: Bolivia, Cochabamba (near Pojo), S. G. Beck 7036 (holotype TEX; isotype LPB), synon. nov.

Aloysia mizquensis Ravenna (2006: 59). Type: Bolivia, Mizque, Ravenna 2500 (holotype LPB n.v.; isotype Ravenna’s private herbarium), synon. nov.

Aloysia ligustrina auct., non Verbena ligustrina Lag. (1816: 18), qua est Verbena genuina.

A small, strongly aromatic shrub in which the branchlets are often somewhat spinescent as in the type of Aloysia beckii. It is distinguished by the small (usually 1 – 2 × 0.5 – 0.8 cm), oblong to oblanceolate, obtuse, entire leaves, which are arranged in opposite pairs and are paler beneath but not white-tomentose. The white, fragrant flowers are arranged in dense, solitary, axillary racemes, usually 2 – 3 cm long but occasionally reaching 5 cm.

Distribution & Habitat. A good example with Koeberlinia spinosa Zucc. and Ruellia erythropus (Nees) Lindau of a species with an amphitropical distribution being found in the United States and Mexico in the northern hemisphere as well as in a large area around the chaco in Brazil, Paraguay, Uruguay, Argentina and Bolivia. In Bolivia it is strictly Andean, being abundant from about 750 – 2800 m in the dry inter-Andean valleys in the south of the country in the Departments of Chuquisaca, Cochabamba, Potosi, Santa Cruz and Tarija. It is found in dry bushland and open dry forest and readily colonises bushy ground around cultivation and abandoned fields.

Selected Specimens Examined. Bolivia. Chuquisaca: Azurduy, 0.5 km N of Molleni towards Sopachuy [19°46′32″S, 64°27′47″W], 2032 m, 12 Dec. 2004, J. R. I. Wood & H. Huaylla 21156 (HSB, K, LPB). Calvo, Centro El Salvador, CIMBOC [20°40′S, 63°10′W], 750 m, 15 April 1993, C. Saravia et al. 11823 (LPB). Oropeza, W edge of Sucre [19°03′S, 65°6′W], 2750 – 2800 m, 18 July 2004, M. Nee 52748 (NY). Zudañez, 30 km E of Tarabuco, 2500 m, 8 March 1981, S. G. Beck 6243 (LPB). Cochabamba: Arce, Anzaldo, 2800 m, May 1987, F. Aleman 122 (LPB). Arque, between Arque and Higuerani, 2650 m, 22 Nov. 1991, P. Ibisch 678 (LPB). Ayopaya, 92 km from Cochabamba passing Morachata towards Independencia, 28 Nov. 1981, S. G. Beck 7426 (LPB). Campero, between Villa Granada and Peña Colorada [18°12′11″S, 65°00′06″W], 2064 m, J. R. I. Wood et al. 21710 (BOLV, HSB, K, LPB); Capinota, between Parotani and Capinota, 14 March 1991, C. Antezana 263 (BOLV, LPB). Cercado, km 12 along road to Santa Cruz, near Sacaba [17°30′S, 66°05′W], 2700 m, Solomon & King 15907 (LPB). Mizque, near Mizque, 2020 m, 11 Feb. 1967, R. Steinbach 664 (LPB). Quillacollo, cono de proyección above Tiquipaya, 2600 m, 20 Jan. 1990, E. Saravia et al. 32 (BOLV). Potosí: Charcas, San Pedro de Buenavista, 2520 m, 16 March 1993, Torrico & Peca 163 (BOLV, LPB). Saavedra, Alto Retiro, between Betanzos and Sucre, 31 March 1993, Torrico et al. 264 (LPB). Santa Cruz: Caballero, NE of Abra del Quiñe [18°04′S, 64°19′30″W], 2100 m, 31 Dec. 1995, M. Nee 46670 (USZ). Cordillera, Alto Parapeti, Hac. Yapuimbia, 800 m, 1 Sept. 1985, Michel et al. 463 (LPB). Florida, 10.5 km SSE of Quirusillas on road from Mairana to Postrervalle [18°24′S, 63°56′W], 1750 m, 31 Dec. 1997, M. Nee 47659 (USZ). Vallegrande, Huascañada, 5 km S of Vallegrande [18°31′5″S, 64°58′W], 2050 m, 4 Jan. 1991, I. G. Vargas 924 (USZ). Tarija: Cercado, Coimata, 2080 m, 18 Dec. 1985, E. Bastian 167 (LPB). O’Connor, Entre Rios [21°32′S, 64°12′W], 29 April 1983, Krapovickas & Schinini 38866 (LPB).

Notes.Aloysia gratissima is a very widespread species and although specimens from Bolivia are relatively uniform, plants from more distant places can look rather different. However, the recent paper by Ravenna (2006) which split this species is almost certainly mistaken as it makes no allowance for infraspecific variation and is clearly based on a very small specimen sample. As with A. citrodora, forms with serrate leaves are occasionally found. Botta (1979: 88) reported var. schulziana (Moldenke) Botta from Bolivia based on Krapovickas et al. 19035, 19210 and 31210 (all SI, n.v.). This is a serrate-leaved variety having an obscurely zygomorphic calyx with somewhat subulate calyx teeth. The only specimen I have seen which seems to conform to this variety is De La Barra 300 (BOLV), collected on Cerro San Pedro, Cochabamba at 2650 m. However the characters used by Moldenke (1940) and Botta (1979, 1993) to distinguish this variety are not entirely satisfactory with the serrate leaves being found mainly in juvenile specimens and the calyx characters very difficult to discern even in Botta’s illustration (1993: 39). There also exist specimens from outside Bolivia with suborbicular, serrate leaves — Botta & Miconi 570 (K) from Cordoba in Argentina is a good example. These can only be separated with difficulty from A. virgata by their smaller size and appear to be examples of introgression between the two species.

5. Aloysia virgata (Ruiz & Pav.) Juss. ex Moldenke (1940: 384). Type: Peru, Pavon (syntype MA, n.v.; isosyntype OXF).

Verbena virgata Ruiz & Pav. (1798: 20).

Lippia virgata (Ruiz & Pav.) Steud. (1841: 751).

Lippia virgata var. platyphylla Briq. (1904: 304). Type: Paraguay, Ascención, Balansa 3116 (holotype G, n.v.; isotype K).

Aloysia virgata var. platyphylla (Briq.) Moldenke (1948: 20).

Lippia virgata var. elliptica Briq. (1904: 304). Type: Paraguay, Ascención, 15 April 1874, Balansa 1016 pro parte (holotype G, n.v.; isotype K).

Aloysia virgata var. elliptica (Briq.) Moldenke (1948: 20).

Aloysia urticoides Cham. (1832: 238). Type: Brazil, Sellow s.n. (holotype LE, n.v. ; possible isotype ex Herb. Benth, K).

Distinguished by the relatively large (4 – 9 × 1.5 – 6 cm), dentate, typically acute leaves arranged in opposite pairs and by the inflorescence of lax, often flexuose, axillary racemes, in which the flower bases are easily visible. The leaves are commonly broadest in the middle and narrowed gradually at both ends and are ovate to elliptic in outline. They are green on both surfaces although often paler and variably hirsute beneath. The lax, flexuose racemes of white flowers, often several per leaf axil, are very characteristic. There is some introgression with Aloysia scorodonoides, which is discussed under that species below. Table 1.
Table 1

Differences between Aloysia virgata and A. scorodonoides.

 

Aloysia virgata

Aloysia scorodonoides

Leaf size

4 – 12 × 1.5 – 4 cm

1.5 – 4.5 (– 5.5) × 1.5 – 3 (–3.5) cm

Leaf shape

Usually acute apex with truncate, rounded or broadly cuneate base

Obtuse apex with cuneate base

Leaf margin

Very variable, crenate to serrate

Regularly crenate

Leaf texture and indumentum

Neither bullate above, nor strongly discolorous, nor tomentose beneath

Bullate, dark green above, grey-tomentose/canescent beneath

Inflorescence

Spikes relatively lax, commonly flexuose, often several per leaf axil and sometimes branched

Spikes dense, straight or curved, solitary per leaf axil, never branched

Flowers

Relatively distant with bases exposed

Imbricate with pedicels and base of calyx covered by next flower

Altitude range in Bolivia and Peru

Always below 2600 m and usually below 1500 m

(1900 –) 2500 – 3650 m

Distribution & Habitat. A lowland species extending around the south of the Amazonian basin from Peru through Bolivia to Brazil and then southwards through the Chaco to Paraguay and northern Argentina. In Bolivia it is frequent in secondary scrub and disturbed bushland up to 1500 m and exceptionally to 2750 m. It is generally scattered in occurrence but is perhaps most frequent around the chaco margins. It is the most lowland of the species discussed here and the only one to occur below 750 m in Bolivia apart from the cultivated Aloysia polystachya.

Selected Specimens Examined. Bolivia. Beni: Vaca Diez, Tumi Chucus, c. 30 km S of Riberalta [11°08′S, 66°10′W], 29 Sept. 1981, J. Solomon 6506 (LPB). Chuquisaca: Calvo, 104 km E of Boyuibe towards Fortin Villazón [20°40′S, 62°40′W], 4 Oct. 1983, S. G. Beck & M. Liberman 9428 (LPB); 4 km N of Guarani military post, 4 – 5 km W of Puesto Iyoe [20°29′S, 62°16′W], 400 m, 19 June 1992, B. Mostacedo et al. 396 (USZ). Oropeza, bottom of descent to Rio Chico from Sucre, 2100 m, 26 March 1995, J. R. I. Wood 9600 (K, LPB). Siles, 50 km from Monteagudo towards Sucre, 1080 m, 1 Oct. 1983, S. G. Beck & M. Liberman 9364 (K, LPB). Zudañez, between Villa Tomina and Zudañez, 2000 m, 29 Oct. 1983, S. G. Beck & M. Liberman 9856 (LPB). Cochabamba, Campero, Aiquile road, between Quiroga and Ajial [18°25.5′S, 65°13.9′W], 2017 m, 21 March 2003, M. Atahuachi et al. 757 (BOLV, K). La Paz, Inquisivi, Mouth of Río Aquilani [16°40′S, 67°20′W], 1400 – 1500, 24 Nov 1991. M. Lewis 40408 (K, LPB, MO); between Cahuata and Miquillas [16°38′42″S, 67°14′21″W], 1750 m, T. Ortuño et al. 344 (LPB, K). Larecaja, Guanai, 600 m, May 1886, H. H. Rusby 1403 (K, NY). Nor Yungas, 3.8 km below Coroico towards Yolosa [16°12′S, 67°404′W], 1500 m, 25 Sept 1996, J. Solomon 15664 (LPB). Sud Yungas, 1.5 km E of Puente Villa [16°24′S, 67°38′W], 1400 m, 29 Sept. 1985, Nee & Solomon 32034 (LPB). Tamayo, P. N. Madidi, Puca Suchu to Virgen del Rosario [14°34′40″S, 68°41′24″W], 910 m, 9 Nov. 2003, A. Fuentes et al. 5849 (LPB). Pando, Madre de Dios, Gonzalo Moreno, 18 km SW of Riberalta [11°04′S, 66°12′W], 8 Sept. 1985, M. Nee 31850 (LPB). Santa Cruz. Caballero, Saipina, 1600 m, Dec. 1959, M. Cardenas 5752 (K), NE of Abra de Quiñe [18°04'S, 64°19′30″W], 2100 m, 31 Dec. 1995, M. Nee 46670 (USZ). Cordillera, Proyecto Abapó-Izazog, 12 March 1981, S. G. Beck & M. Liberman 6448 (LPB); 5 km N of Boyuibe on road to Camiri, 700 m, 21 March 2000, J. R. I. Wood 16082 (LPB, K). Florida, 2 km NW of turn-off from highway at Rio Seco towards La Florida [1618°39.6′S, 63°15.24′W], 540 m, 15 Nov. 2000, M. Nee 51441 (USZ); 4 – 8 km N of Hierba Buena along road to Piedra Mesa [17°55.15′S, 64°02.59′W], 1044 m, 11 March 2003, J. R. I. Wood et al. 19660 (K, LPB, USZ). Guarayos, 9 km E of Ascención de Guarayos, 30 Aug. 1985, S. G. Beck 12292 (LPB). Ibáñez, Río Piraí near former Jardín Botánico, Santa Cruz [17°47′S, 63°13′W], 420 m, 8 July 1987, M. Nee 35076 (K, LPB,NY). Ichilo, 4 km SW of Buenavista [17°429′S, 63°41′W], 315 m, 3 Oct. 1990, M. Nee 51441 (USZ). Ñuflo de Chavez, Jinca, 90 km SE of Concepción [16°33′S, 61°40′W], 450 m, 25 July 1985, T. Killeen 1077 (USZ). Santiesteban, 15.5 km N of Mineros [16°59′S, 63°12′W], 225 m, 28 Aug. 1996, M. Nee 47095 (USZ). Vallegrande, between El Trigal and Mataral, just north of pass [18°12′S, 64°12′W], 1725 m, 9 March 1988, M. Nee & J. Solomon 36569 (USZ). Velasco, 32 km S of San Rafael along road to San Jose [17°03′S, 60°36′27″W], 293 m, 21 Oct. 2007, J. R. I. Wood et al. 23673 (K, LPB, USZ). Tarija, Gran Chaco, 7 km N of Villamontes, 6 May 1983, Krapovickas & Schinini 39211 (CTES, LPB).

Notes.Aloysia virgata is a very variable species in the size, shape, dentation and indumentum of the leaves. Some of this variation has been formally recognised. In the type the leaves are ovate whereas in var. elliptica and var. platyphylla they are essentially elliptic but as all kinds of intermediate are found I have treated these as synonyms. Beck & Liberman 9856 and Solomon 6506 have deeply incised leaves and correspond to var. argutedentata Moldenke (1984) although I doubt this kind of variation merits recognition.

6. Aloysia scorodonoides (Kunth) Cham. ex Moldenke (1940: 382). Type: Ecuador, Quito, Humboldt & Bonpland s.n. (holotype P).

Lippia scorodonoides Kunth (1818: 269).

Lippia scorodonoides var. hypoleuca Briq. (1896: 338). Types: Bolivia, Sorata, Mandon 582 (syntype G, n.v.; isosyntype K) & Peru, Dombey 259 (syntype G, n.v.).

Lippia scorodonoides var detonsa Briq. (1896: 339). Type: Colombia, Hartweg 1349 (isotype OXF).

Aloysia boliviensis Moldenke (1982: 18). Type: Bolivia, La Paz, Mecapaca, J. Solomon 7410 (holotype TEX; isotypes LPB, MO), synon. nov.

Like Aloysia virgata this species is characterised by its dentate leaves in opposite pairs with the flowers arranged in axillary racemes. However, the leaves are smaller, 1.5 – 4.5 (– 6) × 1.5 – 3 (– 3.5) cm, always ovate to suborbicular with an obtuse apex, an abruptly cuneate base and the margin regularly and neatly crenate. The upper surface of the leaf is bullate and the undersurface white-canescent to white-tomentose. The racemes are always solitary in the leaf axils, straight or slightly curved, very dense with imbricate flowers, their bases hidden.

Variation. There is a continuum of forms within Aloysia scorodonoides from plants with obtuse leaves < 2 cm long at one extreme to those with subacute leaves up to 5.5 cm long, distinguishable from Aloysia virgata with difficulty, at the other. For convenience the extreme forms are treated as varieties in this paper but it should be noted that they are not clearly demarcated from other forms along the continuum of variation.

The type of Aloysia scorodonoides corresponds to forms with relatively large, ovate to suborbicular, rounded leaves 3 – 5.5 × 2 – 3.5 cm, of which collections from Ecuador, such as Lehmann 4959 (K), Lewis & Klitgaard 2985 (K), Lewis et al. 391 (K) and Asplund 7010 (K) are representative. They do not grow above 2800 m. One similar form from Bolivia was described as var. hypoleuca by Briquet (1896: 338). As the white undersides of the leaves, from which the varietal epithet is taken, are a defining characteristic of the species as a whole, I regard this as a synonym of the typical variety, as apparently did Briquet, thus implying that the varietal name was superfluous. Another form from Colombia with nearly concolorous leaves distinctly pubescent on the underside was described as var. detonsa by Briquet in the same paper and is also treated here as a synonym of the type variety.

In southern Peru and northern Bolivia, Aloysia scorodonoides reaches at least 3600 m. Plants with leaves < 2.5 cm long which grow in Bolivia in the La Paz area and the nearby Luribay valley above 3000 m are treated below as var. parvifolia Moldenke (1977: 437). A. depressa is a synonym of this variety at specific rank. In the same valleys and other valleys in La Paz Department are forms with larger leaves similar to typical A. scorodonoides as well as forms which intergrade with var. parvifolia. One extremely odd form with leaves in whorls of four was described as A. boliviensis Moldenke. Close examination of the isotype at LPB shows that the leaves are actually in opposite pairs but the internodes are extremely short, something also seen (although less extremely) in Eyerdam & Beetle 22129 (K) from Arequipa in Peru. I do not believe these plants are any more than aberrant forms of A. scorodonoides and, in any case, have not been recollected in Bolivia.

At the other extreme are forms which are difficult to separate from Aloysia virgata. Usually A. scorodonoides can be distinguished from A. virgata by the characters given in the key and in Table 1. However the distinctions between A. scorodonoides and A. virgata are not entirely convincing as there exist specimens from Argentina, Bolivia and Peru which cannot easily be assigned to one or other of these species. These correspond to var. mathewsii (Briq.) Moldenke. Curiously all those that I have seen from Bolivia and Peru were collected around 2000 m, the altitude at which the ranges of the two species overlap. It should be noted that varietal status may, in fact, obscure their real position as intermediates between the two species.

The three varieties of Aloysia scorodonoides accepted here can be distinguished by the following key although some intermediate specimens may be difficult to assign.
  • 1. Leaves < 2.5 cm long . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . var. parvifolia

  • Leaves > 2.5 cm long . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

  • 2. Leaves usually < 4 cm long but, if longer, white tomentose beneath and with obtuse apices, evenly serrate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . var. scorodonoides

  • Some leaves > 4.5 cm long, pubescent but not white-tomentose beneath, subacute, somewhat unevenly serrate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . var. mathewsii

var. scorodonoides

Distribution & Habitat. Widely distributed along the Andes from Colombia to northern Argentina from 2400 – 3300 m but the exact distribution uncertain because of confusion with other species and varieties. In Bolivia, only in the northern Andes.

Specimens Examined. Bolivia. Cochabamba: Capinota, just N of Playa Ancha, 2400 m, 4 March 2002, J. R. I. Wood 17704 (K, LPB). La Paz, Inquisivi: between Yamora and Micayani [16°56'S, 67°07'W], 2550 – 2650 m, 14 Jan. 1987, M. Nee 37593 (LPB). Larecaja: Sorata, Mandon 582 (K); near Gruta San Pedro, Sorata, 2600 m, 28 March 1991, S. G. Beck (LPB); ibid, 2500 m, 27 March 1994, J. R. I. Wood 8178 (K, LPB). Murillo, below Obrajes, La Paz, 14 April 1919, O. Buchtien 557 (K); Sehuencoma, 10 Nov. 1957, J. Cañigueral 337 (LPB); La Paz-Calacota, near Puente Lipari, 3000 m, 13 April 1986, S. G. Beck 14000 (LPB); Río Abajo, SW of Japapina, 3100 – 3300 m, 12 Feb. 1987, S. G. Beck 14223 (LPB); Japapina, 3270 m, 12 Feb. 1987, E. Vargas 87 (LPB); Hac. Huajchilla, 18 km SE of La Paz along Rio La Paz [16°39′S, 68°04′W], 3000 m, Solomon & Kuijt 11491 (LPB); ibid. [16°38′S, 68°03′W], 14 Feb. 1987, J. Solomon & M. Nee 16060 (K, LPB). Potosi: Linares, Valle de Oronkhota, 2520 m, 4 April 1993, G. Torrico & C. Peca 315 (BOLV).

var. parvifoliaMoldenke (1977: 437). Type: Bolivia, La Paz, H. H. Rusby 920 (holotype NY; isotype K). Fig. 1H – J.
https://static-content.springer.com/image/art%3A10.1007%2Fs12225-009-9131-5/MediaObjects/12225_2009_9131_Fig1_HTML.gif
Fig. 1

AEAloysia axillaris (typical form from Torotoro). A habit; B leaf; C flower; D calyx; E corolla opened out to show stamens, ovary and style. FGAloysia axillaris (form from La Cabaña). F habit; G leaf. HJAloysia scorodonoides var. parvifolia.H habit; J leaf. AE from J. R. I. Wood, M. Mercado & T. Ortuño 21305, FG from J. R. I. Wood 20173, HJ from T. Ortuño 209. Drawn By Rosemary Wise.

Aloysia depressa Ravenna (2007: 15). Type: Bolivia, La Paz, Coello-Jurado (holotype BA, n.v.), synon. nov.

Distribution & Habitat. Only known from the High Andes of southern Peru and northern Bolivia where it grows in very arid inter-Andean valleys between 3000 – 3650 m.

Specimens Examined. Bolivia. Loayza, 27 km along road to Sapahaqui [16°55′S, 67°55′W], 3450 – 3650 m, 18 Jan. 1981, S. G. Beck 6039 (LPB); 27 km along road towards Sapahaqui [16°55′S, 67°55′W], 3450 – 3650 m, 18 Jan. 1981, S. G. Beck 6040 (LPB); between Sapahaqui and Kuri, 3500 m, 7 April 1990, S. G. Beck 17542 (LPB); camino de Calamarca a Sapahaqui [16°52.95′S, 67°58.89′W], 3343 m, 27 Feb. 2002, T. Ortuño 209 (K, LPB). Murillo, near La Paz, 3000 m, Oct. 1885, H. H. Rusby 920 (K, NY); Vic. La Paz, 3000 m, 1889, M. Bang (K); Mecapaca, 3070 m, 24 April 1980, S. G. Beck 3530 (LPB); Rio Abajo, c. 4 km above Mecapaca, 3000 m, 8 Jan. 1995, J. R. I. Wood 9148 (K, LPB).

var. mathewsii (Briq.) Moldenke (1934: 95). Type: Peru, Mathews 3160 (holotype G; isotypes K, OXF).

Lippia scorodonoides Kunth var. mathewsii Briq.(1896: 339).

Lippia peruviana Turcz. (1863: 201). Type: Peru, Mathews 585 (holotype ?KW, n.v., isotypes K, OXF), synon. nov.

Aloysia peruviana (Turcz.) Moldenke (1937: 15).

Distribution & Habitat. Recorded from scattered localities from Andean Peru south to northern Argentina. In Bolivia an uncommon plant of dry bushland in the inter-Andean valleys between 1800 – 2100 m.

Specimens Examined. Bolivia. Chuquisaca: Tomina, between Padilla and Monteagudo, 20 Sept. 1980, Mühlbauer s.n. (LPB). Cochabamba, Campero, Pasorapa, Pasarapilla [18°22.02′S, 64°32.89′W], 2084 m, 28 Dec. 2004, J. R. I. Wood, M. Atahuachi & M. Mercado 21265 (BOLV, K, LPB). Potosí: Saavedra, between Puente Mendez and Millares, 2100 m, 15 Jan. 1997, J. R. I. Wood 11676 (K, LPB). Santa Cruz: Caballero, Saipina, Dec. 1959, M. Cardenas 552 (K); Abra del Vilcar, Estancia El Junco, Saipina [18°05′S, 64°31′30″W], 1800 m, 22 Oct. 1994, J. Balcazar 63 (USZ).

7. Aloysia axillarisJ. R. I. Wood. sp. nov. ex affinate A. scorodonoidis a qua differt pilis rectis, patentibus (non crispis, adpressis), foliis ovatis (non ellipticis), cordatis vel truncatis (non cuneatis), 3 – 13 mm longis, floribus solitariis in axillis foliorum dispositis et interdum etiam in racemis axillaribus laxis, basibus florum expositis (non semper in racemis densis, floribus imbricatis) et stylo breve. Typus: Bolivia, Potosi, Torotoro, J. R. I. Wood. M. Mercado & T. Ortuño 21305 (holotypus K; isotypi BOLV, LPB).

Much branched aromatic undershrub to 1.5 m, the stems erect, sparingly branched and somewhat strict when not chewed down, woody except the newest growth, pale brown, pubescent when young, glabrescent when older. Leaves borne on short brachyblasts c. 1 mm in length, petiolate, opposite, subopposite to slightly alternate; petioles c. 1 mm long, pubescent with spreading glandular and eglandular hairs; lamina 3 – 14 × 2 – 9 mm, ovate, obtuse, weakly cordate to truncate at the base, margin crenate-dentate, upper surface dark green, strongly bullate with deep channels, pubescent with spreading hairs, the lower surface paler, dotted with pale yellow glands, grey-pubescent in the intercostal area with paler, more sparsely pubescent high-lighted veins. Inflorescence of two kinds one or other of which tends to predominate: solitary axillary flowers borne without bracteoles towards the branch tips and pedunculate axillary spikes, in which the flowers are borne in the axils of bracteoles, the axillary spikes sometimes completely absent; spikes (where present), pedunculate, 5 – 25 mm long, 6 – 20-flowered; peduncles arising from leaf axils. c. 5 mm long, pubescent; flowers very shortly pedicellate, the pedicels 0.5 – 1 mm long; bracteoles 2.5 × 1 mm, ovate, acuminate with a claw-like base, entire apart from a single marginal tooth, pubescent; calyx 2.25 – 2.5 mm long, campanulate, 5-lobed to nearly half way, densely white-pubescent, the lobes narrowly triangular, c. 1 mm long, slightly less hairy than the tube; corolla 4.4 – 5 mm long, very pale pink, 4-lobed, tube 3 – 3.5 × 1 mm, densely pubescent especially in upper half, lobes 1.5 × 1.5 mm, ovate, acute, nearly glabrous, corolla mouth blocked with a mass of hairs; anthers 4, inserted just below mouth, sessile, oblong, c 0.5 × 0.25 mm; style 1.25 – 1.5 mm long, glabrous, stigma weakly clavate; nutlets 0.75 × 1 mm, broadly ovate, glabrous. Fig. 1A – G.

Distribution & Habitat. On sandstone and limestone rock outcrops and cliffs between 2500 – 2625 m in two areas of the inter-Andean dry valleys of Bolivia.

Specimens Examined. Bolivia. Cochabamba: Quillacollo, 1 – 2 km E of Parotani along road to Cochabamba, c. 0.7 km before La Cabaña, 2500 m, 7 Feb. 2004, J. R. I. Wood 20173 (BOLV, K, LPB); near La Cabaña in canon del Rio Rocha, between Suticollo and Parotani [17°19.22′S, 66°12.05′W], 2550 m, 3 Feb. 2005, J. R. I. Wood & M. Atahuachi 21575 (BOLV, K, LPB). Potosí: Charcas, Cañon del Vergel, Torotoro [18°06.12′S, 65°45.97′W], 2625 m, 25 Feb. 2003, J. R. I. Wood. M. Mercado & M. Atahuachi 19286 (BOLV, K, LPB); ibid. [18°06.87′S, 65°46.45′W], 2551 m, 3 Jan. 2005, J. R. I. Wood, M. Mercado & T. Ortuño 21305 (BOLV, K, LPB).

Conservation Status. Although restricted to two areas, this plant is quite common at both localities. One lies within the Torotoro National Park. In both, the plant grows on steep rock slopes where it is often inaccessible. It is of Least Concern (LC) following the IUCN (2001) criteria despite its restricted distribution.

Notes. This species is inconspicuous but common on rocky slopes around Torotoro, where all plants observed over several years have inflorescences composed only of axillary flowers. Plants from the zone of La Cabaña in the gorge lying between Suticollo and Parotani seem always to have two kinds of inflorescence, some flowers are axillary and some are arranged in axillary spikes. Axillary flowers are always present and the spikes are noticeably laxer than those of Aloysia scorodonoides (Fig. 1). There are no populations of A. scorodonoides in the immediate neighbourhood of La Cabaña, but it occurs some 15 km distant near Capinota so it is just possible that this population is of hybrid origin, although there is no evidence except this tenuous geographic link and the dimorphic inflorescences to support this hypothesis. Whatever the status of the Cabaña populations, A. axillaris is unique in Aloysia because of the presence of axillary flowers. The population at La Cabaña could be confused with plants treated as A. scorodonoides var parvifolia but can always be distinguished by the presence of some axillary flowers, the laxer spikes with flower bases clearly exposed, the cordate or truncate (not cuneate leaf bases) and the spreading hairs on the inflorescence. In addition the Cabaña population lies at around 2500 m, while all known populations of small-leaved A. scorodonoides are found between 3000 and 3650 m.

Footnotes
1

This label bears the name Aloysia scorodonoides, under which the type was distributed (Macbride 1960: 650)

 

Acknowledgements

I would like to express my thanks to Rosemary Wise for the preparation of the illustration which accompanies this paper and to various colleagues who accompanied me in the field when I was studying and collecting Aloysia, particularly Teresa Ortuño, Magaly Mercado, Margoth Atahuachi, Hibert Huaylla, Julia Gutiérrez and Martha Serrano. Thanks are due to Sandy Atkins and two anonymous reviewers for comments on an earlier draft of this paper. I am also grateful to the directors of BOLV, HSB, LPB and USZ for access to their collections in Bolivia. This paper describes yet another new species discovered during the Darwin Initiative Project no. 11-010 whose support is gratefully acknowledged.

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