Dioscorea cumingii Prain & Burkill

No material from Yunnan has been seen by the present authors, and the record from there requires confirmation, especially because there are no other records from the Asian mainland.

Rootstock unknown. Stem twining to left, minutely yellow puberulent, prickly. Leaves alternate, palmately (3 or)5- or 7(or 9)-foliolate; petiole 7--9 cm; middle leaflet lanceolate, 8--12.5(--18) × 3--4.2 cm, ± herbaceous, puberulent, glabrescent except along veins, pinnately veined, base attenuate into indistinct petiolule, margin entire, apex caudate-acuminate; lateral leaflets obliquely elliptic, 6.5--9 × 2.3--3.2 cm, usually ± 2-veined from near base. Male spikes to 1.5 cm, in axillary panicles to 50 cm with 2 levels of branching, most parts densely gray tomentose. Male flowers: solitary; pedicel to 0.6 mm; bract and bracteoles forming involucel around perianth, bract cordate, ca. 1.5 mm, longer than perianth, bracteoles ovate, equaling perianth, tomentose, apex caudate; perianth drying dark, glabrescent, outer lobes oblong-ovate, to 2 mm, inner ones slightly smaller than outer; stamens 3; staminodes longer than stamens. Female spike solitary, 16--30 cm. Capsule oblong, 4--5 cm, puberulent when young, glabrescent, base cuneate, apex rounded; wings 0.9--1.3 cm wide. Seeds inserted near apex of capsule; wing pointing toward capsule base, ca. 0.9 × 0.5 cm. Fl. Apr, fr. Aug--Feb.

Taiwan (Lan Yu opposite SE coast), ?Yunnan [Indonesia, Philippines].

Dioscorea cumingii var. inaequifolia (Elmer ex Prain & Burkill) Burkill; D. cumingii var. polyphylla (R. Knuth) Burkill; D. heptaphylla Sasaki; D. inaequifolia Elmer ex Prain & Burkill; D. polyphylla R. Knuth.