Smilax pekingensis A. de Candolle; S. tenuissima Hayata; S. vaginata Decaisne; S. vaginata var. pekingensis (A. de Candolle) T. Koyama; S. vaginata var. stans (Maximowicz) T. Koyama.

Shrubs deciduous, erect, unarmed. Stem densely branched, 0.3--3 m. Petiole 5--12 mm, abaxially striate-ridged, narrowly winged for ca. 2/3 its length; wings apically confluent to petiole; abscission zone subapical; tendrils absent. Leaf blade abaxially glaucous, ovate to suborbicular, 1.5--4(--6) × 1.2--3.5(--5) cm, sometimes abaxially slightly powdery. Inflorescence of 1 umbel, basally not prophyllate; peduncle slender, 0.7--2 cm; umbels of both sexes 1--3(--6)-flowered, base not thickened. Male flowers: tepals yellowish green or sometimes pink, 2.5--3 × 0.7--1 mm. Female flowers: tepals slightly smaller than male ones; staminodes 6. Berries black, globose, 6--10 mm in diam., white powdery. Fl. Mar--May, fr. Oct--Nov.

Forests, thickets, shaded places on grassy slopes; 400--3200 m. Anhui, Gansu, Guangdong, Guangxi, Guizhou, ?Hebei, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Shaanxi, Shanxi, Taiwan, ?Yunnan, Zhejiang [Japan].