MUCUNA ADANS. (LEGUMINOSAE) IN THAILAND (C.M. WILMOT-DEAR)
Distribution.— Cultivated widely in the tropics. Ecology.— Cultivated (possibly also naturalised).
Notes.— Its fruits are easily distinguished from those of the other varieties and the similar species M. bracteata by the dense covering of soft hairs (rather than irritant bristles) and the irregular sizes of the often much larger swellings around each seed. Flowering specimens are often not distinguishable from the typical variety (which can also lack irritant bristles from flowers and leaves) but the leaflets of var. utilis sometimes differ in relative proportions, lateral leaflets being often much larger than terminal one and terminal leaflet very broad.
12. Mucuna bracteata DC. ex Kurz, J. Asiat. Soc. Bengal Pt. 2, Nat. Hist. 42: 231. 1873; Gagnep. in H.Lecomte, Fl Indo-Chine 2: 323. 1916;Van Thuan, Fl. Camb. LaosVietnam 17: 32. 1979; Wilmot-Dear in Kew Bull. 47: 240 & Fig. 11. 1992. Types: Burma, Pegu [Martaban, Ava, ?Kurz s.n. (syntypes CAL); Roxburgh drawing 138 (syntype ?CAL; copy K)].— M. brevipes Craib, in Bull. Misc. Inform. Kew 1927:378. 1927 & Fl .Siam 1: 443. 1928. Type: Thailand. Northern, Chiang Mai [Doi Sutep, Kerr 1572B, holotype K!, isotype BM!)]. Figs. 1 X–Z, 2 Q–R.
Slender climber; stems and petioles glabrous to densely covered with short, pale, adpressed hairs. Leaves and leaflets very variable in size; terminal leaflets 7–14 by 5.5–11(– 13) cm, rhombic (rarely broadly elliptic), lateral veins 5–7 pairs, apex acute (rarely acuminate), base rounded; lateral leaflets with base of abaxial half truncate; lateral veins scarcely curved, often dark and thickly prominent at least beneath, scalariform tertiary venation often prominent beneath; mostly rather thick-chartaceous and markedly paler beneath; rarely glabrous, usually with sparse to abundant, short, fine, adpressed (or spreading) pale hairs above especially on veins, hairs denser beneath but conspicuously less dense on veins; stipules 2–5 mm, usually robust. Inflorescence 10–41 cm long, main axis often thick and robust even in flower, rarely once-branched close to base or a pair arising from same axil, ultimate branchlets 10–many, knob-like, often all in upper of axis but bracts or scars always present in lower, flowerless region; pedicels and axis with dense, short, spreading, pale or dark brown pubescence and frequent fine bristles; bracts and bracteoles conspicuous and long-persistent, often even to fruiting stage, 8–24 & 2–10 mm, of very varied form, lowermost bracts mostly long-acuminate, narrowly ovate or triangular, upper (flowering) bracts mostly obovate broadly rounded; bracteoles obovate, ovate or linear-ovate, rounded or acute to acuminate. Calyx with hairs and fine bristles like the axis; lobes short and broadly triangular, lowest (3–)5–6 mm long, laterals 2–4 mm long, upper lip often exceeding laterals. Corolla dark purple, petals as in M. pruriens. Fruit linear-oblong, often slightly wider than in M. pruriens, 6–9 by 1–1.5 cm, straight or slightly curved. Seeds ellipsoid as in M. pruriens, 1–2 cm long, brown or black usually with pinkish brown mottling; rim-aril black.
Thailand.— NORTHERN: Chiang Mai [Doi Sutep, Kerr 1572B (BM, K)], Chiang Rai [Maxwell 94–1304 & 97–1396 (BKF, GH)], Lampang, Lamphun [Maxwell 94–182 (BKF, GH)], Phrae, [Konta et al. 4462 (BKF)]; NORTHEASTERN: Loei [Phu Kradueng, Shimizu et al. 22746 (BKF)]; EASTERN: Chaiyaphum; SOUTHWESTERN: Kanchanaburi; PENINSULAR: Phuket.