This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier’s archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/copyright Author's personal copy Available online at www.sciencedirect.com South African Journal of Botany 78 (2012) 178–194 www.elsevier.com/locate/sajb A revision of the genus Dolichos (Fabaceae, Papilionoideae, Phaseoleae), including Lesotho and Swaziland ⁎ A.N. Moteetee , B.-E. Van Wyk University of Johannesburg, Department of Botany and Plant Biotechnology, P.O. Box 524, Auckland Park 2006, Johannesburg, South Africa Received 9 March 2011; received in revised form 21 June 2011; accepted 22 June 2011 Abstract A revision of the genus Dolichos in South Africa (Lesotho and Swaziland included) is presented. This legume genus, belonging to the bean tribe Phaseoleae, mainly has an African distribution, extending into Asia. In South Africa it is represented by nine species, two (D. sericeus and D. trilobus) of which extend into Tropical Africa. Dolichos is closely related to the genus Macrotyloma from which it can be distinguished by the short standard appendages, reticulate pollen and the generally purple flowers (standard appendages long, pollen tuberculate or spinulose and flowers yellow or orange in Macrotyloma). It also has affinities with the genera Dipogon and Lablab. The correct nomenclature, as well as complete synonymy, typification and distribution maps of all the species are provided. © 2011 SAAB. Published by Elsevier B.V. All rights reserved. Keywords: Chloryllis; Dipogon; Lablab; Macrotyloma; Phaseolinae; Taxonomy 1. Introduction he divided Dolichos s.l. into several groups now recognised as genera, including Austrodolichos Verdc., Macrotyloma (Wight & The genus Dolichos L. belongs to the subtribe Phaseolinae of Ar.) Verdc., Nesphostylis Verdc., Pseudeminia Verdc., Pseudo- the Phaseoleae tribe (family Fabaceae, subfamily Papilionoideae). vigna (Harms.) Verdc. and Sinodolichos Verdc. (Verdcourt, Distinguishing characteristics of the subtribe Phaseolinae include 1970; Mackinder, 2001). The latter three genera are now placed in expanded, flattened or coiled styles, presence of appendages on the subtribe Glycininae (Lackey, 1981). Verdcourt (1970) also the standard petal, keel petals that are usually fused along both established the concept of Dolichos s.s., which he subdivided into margins and perhaps most importantly, the presence of a white three subgenera Dolichos, Chloryllis (E. Mey.) Verdc. and spongy tissue that covers the hilum (Lackey, 1981). Odontichos Verd. Dolichos subgenus Odontichos can be dis- Dolichos is chiefly African but also extends to Asia (Baker, tinguished by, among other characters, the presence of a tooth at 1871; Mackinder, 2001). The origin of the name Dolichos is the base of the vexillary filament, uniformly thickened style (style unclear, but apparently “it was used by Dioscorides for some thickened at the base in subgenera Dolichos and Chloryllis)and similar plant, or for some species of the allied genus Phaseolus L. conspicuous bracteoles. Dolichos subgenus Chloryllis is char- (kidney-bean)” (Harvey, 1862). Adamson and Salter (1950) noted acterised by greenish-yellow flowers, a nodulate inflorescence that it is “a Greek name for a plant with edible pods”.Accordingto rachis and the curved style apex. Verdcourt (1978), the name is derived from a Greek word for Dolichos s.s. is a relatively large genus comprising about 60 “long”. A comprehensive background to the taxonomic history of species (Mackinder, 2001). It is closely related to Macrotyloma, the genus Dolichos was given by Verdcourt (1970).Inthiswork, from which it differs in having short standard appendages (long and narrow in Macrotyloma), reticulate pollen (tuberculate or ⁎ Corresponding author. Tel.: +27 11 5592977; fax: +27 11 5592411. spinulose in Macrotyloma) and the generally purple, purplish E-mail address: [email protected] (A.N. Moteetee). pink or violet flowers (yellow or orange in Macrotyloma; 0254-6299/$ - see front matter © 2011 SAAB. Published by Elsevier B.V. All rights reserved. doi:10.1016/j.sajb.2011.06.012 Author's personal copy A.N. Moteetee, B.-E. Van Wyk / South African Journal of Botany 78 (2012) 178–194 179 Verdcourt, 1970; Mackinder, 2001). Recent molecular data has D. linearis both have linear–lanceolate leaflets, but the leaflet base revealed that Dolichos is successively a sister to Macrotyloma and in the former is cuneate while it is round in the latter. Furthermore, Sphenostylis E. Mey. (Wojciechowski et al., 2004). Sphenostylis in D. angustissimus the leaflets tend to be conduplicate. In differs from the other two genera in having a laterally flattened D. pratensis there are prominent diagnostic mucrons on the leaflets. style. Dolichos also has affinities with the monotypic genera Petioles length is of limited diagnostic value but can be used to Dipogon Liebm. and Lablab Adans, with which it is often con- distinguish between the two closely related species D. sericeus (up fused. Lablab can be distinguished from Dolichos and related to 25 mm long) and D. triblobus (up to 70 mm long). genera by several characters including a blade-like style; a non- penicillate stigma and verrucose margins (Fig. 1) on the pods 3.2. Reproductive morphology (Verdcourt, 1978). While, Dipogon differs in that the base of the style is strongly curved in the same direction as the apex. In most species, the peduncles are longer than the petioles, Nine species of Dolichos occur in South Africa, including two apart from two species (D. linearis and D. trilobus) where they (D. trilobus and D. sericeus) which extend into Tropical Africa. are shorter. In D. peglerae and D. pratensis, the peduncles are diagnostically nodulose. Bracts and bracteoles are usually 2. Materials and methods persistent, except in D. peglerae and D. pratensis where they are caducous at a very early stage. Flower colour is mostly Plant material was studied during field trips and mainly from purple, purplish-pink or violet, except in D. pratensis where the herbarium specimens loaned from BOL, NBG (including SAM) flowers are green or greenish yellow. The calyx is generally and PRE, and those housed in BM, GRA, JRAU, K, NH, NU, S shorter than the corolla and bilabiate in all species. The shape of and UPS. the calyx lobes is of limited diagnostic value, e.g. D. decumbens and D. falciformis have similar leaf morphology but the calyx 3. Results and discussion lobes are round in the former and triangular in the latter. The standard petal is characterised by the presence of short, cone- 3.1. Vegetative morphology shaped appendages in all species. The keel petals are equal to or longer than the wing petals, but in D. peglerae and D. pratensis The South African species of Dolichos are trailing, twining, the keel petals are almost twice as long as the wings. prostrate or erect shrublets or suffrutices. Leaflet morphology is an important taxonomic character for distinguishing between species. 4. Taxonomic treatment The leaflets can be linear, linear–lanceolate, lanceolate, hastate (D. hastaeformis), broadly elliptic, ovate, rhombic-ovate or slightly Dolichos L., Sp. Pl.: 725 (1753) & Gen. Pl. ed. 5: 324 (1754); or distinctly tri-lobed (D. trilobus). Dolichos angustissimus and nom cons. Adans., Fam. Pl. 2: 325 (1763); Willd., Sp. Pl.: 1037 A B C D Fig. 1. Leaves, flowers and fruits of various species of Dolichos and Lablab: D. linearis (A), D. decumbens (B) and D.falciformis (C); flowers and warty fruits of Lablab purpureus (D). Photographs: a, c, d, B-E. Van Wyk; b, T. Van Wyk. Author's personal copy 180 A.N. Moteetee, B.-E. Van Wyk / South African Journal of Botany 78 (2012) 178–194 (1802); DC., Prod. 2: 397 (1825); Benth. & Hook. f., Gen. Pl. 4a. Erect, robust suffrutex, leaflets usually conduplicate 1: 540 (1865); Eckl. & Zeyh., Enum. 2: 258 (Jan, 1836); E. Mey., (folded double lengthwise); base cuneate; peduncles longer than Comm. Pl. Afr. Austr.: 140 (Feb, 1836); Harv., Fl. Cap. 2: 242– petioles ............................. 1. D. angustissimus. 243 (1862); Bak., Fl. Trop. Afr.: 209 (1871); Taub. in Engl. & 4b. Prostrate, sparingly branched suffrutex, leaflets rarely Prantl, Natur. Pflanzenfam.: 383 (1894); Bak. f. in Leg. Trop. conduplicate; base round; peduncles shorter than petioles ...... Afr.: 429 (1929); E.P. Phillips, Fl. Pl. S. Afr.: 427 (1951); Verdc. .......................................................... 5. D. linearis. in Kew Bull. 24: 389 (1970); Gillett et al. in Fl. Trop. E. Afr.: 674 3b. Leaflets broadly elliptic, ovate, rhombic or rhombic-ovate. (1970); B. Mackinder in Flora Zambeziaca 3(5): 84 (2001). Type 5a. Peduncles nodulose; keel longer than wings .......... species: D. trilobus L. .................……. 6. D. peglerae. Lablab Adans., Fam. Pl. (Adanson) 2: 325 (1763); DC., 5b. Peduncles not nodulose; keel equal to or shorter than Prod. 2: 401 (1825), pro parte excl. type. wings. Lablavia D. Don in Sweet, Brit. Flow. Gard. Ser. II. t.236 6a. Leaflets relatively large (up to 90 mm long), sometimes (1834). slightly or distinctly tri-lobed. Macrotyloma Wight & Arn.: 247 (1834), pro parte excl. 7a. Stems and leaves densely villous; bracteoles up to 7 mm type. long; carinal calyx lobe longer than the two lateral ones …....... Chloryllis E.Mey., Comm. Pl. Afr. Austr.: 149 (Feb, 1836). ….......………………..…............. 7. D. sericeus. Dipogon Liebm., Ind. Sem. Hort. Hafn., in Ann. Sc. Nat. Ser. 7b. Stems and leaves sparsely pubescent; bracteoles very IV. ii.: 376 (1854), pro parte excl. type. small (up to 2 mm long); carinal calyx lobe equal to the two Shrubs or suffrutices with trailing and/or twining branches lateral ones …..………..……………… 8.