17. Mucuna incurvata Wilmot-Dear & R. Sa, Fl. China. 10: 218. 2010.
喙瓣黧豆 hui ban li dou
Type: China. Yunnan, "Che Li Dist., Ban-chiou Chian" [Jinghong County], Oct 1936, C. W. Wang 79571 (holotype, PE; isotype, A).
Paratypes: C. W. Wang 79233 (A, PE).
Mucunae prurienti similis sed lobis lateralibus calycis duplo longioribus c. 6 mm (nec 2-4 mm tantum) longis atque multo latioribus 4-5 mm (nec 2-3 mm tantum) latis, calyce extus setulas multo tenuiores ferenti, carina ad apicem multo magis incurvata atque per 1 cm longitudinis indurata et foliis infra cauleque pilos longiores ferentibus differt.
Twining vines. Young stems with dense spreading or adpressed long fine golden hairs. Leaves ca. 29 cm; petiole 13-15 cm with short adpressed fine pale hairs; stipels robust, tapering to tip, 2-4 mm; leaflets thinly papery or membranous, adaxially with abundant fine short pale adpressed hairs giving shiny appearance, abaxially with similar denser longer (ca. 1 mm) hairs but with veins dark and conspicuously less pubescent, lateral veins 5 or 6 pairs, slender, straight or slightly curved, running right into margin; terminal leaflet elliptic or rhombic-ovate to rhombic-obovate, ca. 11 × 7 cm, base broadly cuneate to rounded, apex broadly acute to broadly rounded; lateral leaflets 9.5-11.5 cm, width ratio of abaxial to adaxial halves 2-2.5:1, abaxial half with base ± truncate. Inflorescence axillary, length and number of nodes unknown; pedicels 3-4 mm, densely adpressed hairy; bracts unknown. Calyx with dense soft adpressed pale hairs and fine golden bristles; tube ca. 6 × 10 mm; lateral 2 lobes broadly triangular, ca. 6 × 4-5 mm, lowest broadly triangular, 8-10 × 4-5 mm. Corolla deep purple; standard ca. 2.2 cm, ca. 1/2 of keel length; wings ca. 4 × 1.4 cm; keel 4-4.5 cm, apex markedly incurved clawlike and horny to ca. 1 cm. Ovary narrowly cylindric, tapering to apex; ovules ca. 4. Mature fruit unknown.
● Mixed forests; 800-900 m. S Yunnan (Jinghong).
This new species is Mucuna "sp. A" of Wilmot-Dear (Kew Bull. 39: 64. 1984). Known only from the two gatherings cited, it is similar to M. pruriens but differs in having lateral calyx lobes twice as long, all calyx lobes much broader, corolla with a much more incurved and clawlike keel, longer hairs on the stem and leaves abaxially, and much finer bristles on the calyx.