Smilax castaneiflora H. Léveillé; S. elegans Wallich ex Kunth subsp. microphylla (C. H. Wright) Noltie; S. gracillima H. Léveillé & Vaniot (1905), not Hayata (1911); S. labordei H. Léveillé & Vaniot; S. microphylla var. angustifolia Warburg.

Vines climbing. Stem branched, 1--5 m, woody; branches minutely prickly. Petiole 0.5--2 cm, narrowly winged for 1/2--2/3 its length; abscission zone apical; tendrils commonly present. Leaf blade abaxially glaucous, ovate-lanceolate to linear-lanceolate, 3--9 × 1--4 cm. Inflorescence of 1 umbel, basally not prophyllate; peduncle strikingly shorter than petiole, usually minutely scabrous; umbels of both sexes 2--15-flowered, base thickened; bracteoles many, small, persistent. Male flowers: tepals greenish, 1.6--2 × 0.7--1 mm; stamens very short. Female flowers: tepals slightly smaller than male ones; staminodes 3. Berries blue-black, globose, 5--7 mm in diam. Fl. Jun--Aug, fr. Oct--Nov.

* Forests, thickets, shaded places on slopes; 500--1600 m. S Gansu, Guizhou, Hubei, Hunan, S Shaanxi, Sichuan, Yunnan.