Smilax siderophylla Handel-Mazzetti.

Vines climbing. Stem branched, subterete, 1--3 m or more, woody; branches usually sparsely prickly. Petiole 2--3 cm, wingless or rarely narrowly winged for ca. 1/2 its length; abscission zone distal; tendrils usually present. Leaf blade elliptic, ovate-elliptic, or orbicular, 5--11 × 3--9 cm, thickly leathery, main veins 3, strongly convex abaxially, concave adaxially. Inflorescence a raceme of 2--4 umbels, 3--5 cm, basally prophyllate; umbels of both sexes 15--25-flowered, base subglobose. Male flowers: tepals yellow, outer ones ca. 6 × 2 mm, inner ones much narrower; stamens ca. 6 mm. Female flowers: tepals smaller than male ones; staminodes 3. Berries black, globose, 5--6 mm in diam. Fl. Mar--Apr, fr. Aug--Oct.

* Forests, thickets, shaded and damp places on slopes; 1800--2700 m. Yunnan.