MUCUNA ADANS. (LEGUMINOSAE) IN THAILAND (C.M. WILMOT-DEAR)
long, wings 5.5–6 cm long, keel equalling wings. Fruit large, (very rarely 2–)3-seeded, 13–14 by 6–7 cm, broadly oblong, markedly laterally flattened, up to 2.5 cm thick; surface with abundant, fine, spreading, red brown hairs and irritant bristles, lamellae 10–15, oblique, bifurcated and interrupted as in M. revoluta and not running into wings but apical halves somewhat upcurved, never revolute; marginal wings flat, very wide, 12–15 mm. Seeds orange-brown, even larger than in M. revoluta, 3 by 2.5 cm, hilum black.
Thailand.— NORTHERN: Chiang Mai, Nan, Lampang [Maxwell 95–149 & 96–1027 (BKF, GH, L)], Phitsanulok [Bandong, Wongprasert et al. 0212–01 (BKF)]; EASTERN: Nakhon Ratchasima [Wongprasert et al. 83 (BKF); Pak Chong, Marcan 1554 (BM)]; SOUTHWESTERN: Prachuap Khiri Khan [Middleton 1255 (AAU, P)]; CENTRAL: Saraburi.
Distribution.— Cambodia, Laos, Vietnam, SW China, Burma.
Ecology.— Evergreen forest and mixed forest in shade or on river banks, secondary forest amongst bamboo, open thickets; 75–600 m alt.
Notes.— 18 collections of M. interrrupta have been seen from Thailand (13 since 1992 of which those here cited represent additional locality records) and it appears to be not uncommon. It is easily recognised in fruit, but vegetatively almost identical to three of the other lamellate-fruited Thai taxa, M. stenoplax, M. hainanensis and M. revoluta. Its relatively large flowers with persistent bracts are often confused with those of M. hainanensis, which differs in its simple fruit lamellae, narrow-acuminate rather than broad- acute calyx lobes and usually purple corolla with upper floral bracts obovate with a hooded apex. M. revoluta is often misidentified as this species but easily distinguished by its extremely short, spreading indumentum on the inflorescence, mostly shorter, usually purple flowers, thick-textured, strongly revolute fruit lamellae and inrolled marginal wing. M. stenoplax has much smaller purple flowers and simple lamellae. The most closely similar species, M. imbricata (known only from NE Himalaya and N Burma) differs only in that its fruits are 2- (never 3-) seeded, lamellae and marginal wing undulate or slightly revolute, calyx lobes narrower and flowers shorter with bracts caducous.
B. Subgenus Stizolobium (P.Br.) Prain.
Annual or sometimes perennial slender climbers. Seeds oblong-ovoid with a very short hilum surrounded by a conspicuous rim-aril. Lateral veins of leaflets running clearly into margin.
10. Mucuna gracilipes Craib, Bull. Misc. Inform. Kew 1927: 378. 1927 & Fl. Siam 1: 444. 1928;Wilmot-Dear, Kew Bull. 47: 233 & Fig. 9A–E. 1992.Type:Thailand, Northern, Lamphun [Me Kaw, init 1541 (holotype K!)]. Fig. 1V–W.
Trailing slender herb, stems with abundant conspicuous long (1–1.7 mm) weak, spreading, pale orange hairs. Leaves and leaflets very similar to those of M. pruriens, terminal leaflet ca 9–10 by 5.5 cm, elliptic, apex rounded and abruptly fine-mucronate, base rounded, lateral veins (5–)6–7 pairs, gently curved and running right into margin; lateral leaflets slightly larger than terminal, markedly asymmetrical with ratio of width of abaxial to adaxial 2.3–3:1, abaxial half with base truncate; rather thick-chartaceous, with hairs like