Smilax luteocaulis H. Léveillé; S. rubriflora Rehder.

Vines deciduous, climbing, unarmed. Stem branched, terete, 0.5--3 m, woody. Petiole 5--12 mm, abaxially striate-ridged, narrowly winged for 2/3--3/4 its length; wings apically confluent to petiole; abscission zone apical; tendrils usually present. Leaf blade abaxially glaucous, ovate or elliptic-ovate, 2--6(--10) × 2--5(--7) cm. Inflorescence of 1 umbel, basally not prophyllate; peduncle 2--4 cm; umbels of both sexes 5--15-flowered, base scarcely thickened. Male flowers: tepals purplish red, ca. 2.5 × 1 mm; stamens 0.6--1 mm; filaments basally connate, forming a short column. Female flowers: tepals subequaling male ones; staminodes 6, sometimes antheriferous. Berries purplish black, globose, 7--10 mm in diam. Fl. May--Jun, fr. Oct--Nov.

Forests, thickets, shaded places on slopes; 2600--3700 m. Gansu, Guizhou, Hubei, Shaanxi, Sichuan, Xizang, Yunnan [Bhutan, N India, Myanmar, Sikkim].