Description from Flora of China
Vines climbing, unarmed. Stem branched, 3--9 m, woody. Petiole 0.8--1.4 cm, narrowly winged for ca. 1/2 its length; wings each with a lanceolate auricle (2--6 mm) apically; abscission zone apical; tendrils usually present. Leaf blade abaxially glaucous, ovate to oblong-elliptic, 4--14 × 2--4.5(--7) cm, leathery, margin recurved. Inflorescence of 1 umbel, basally not prophyllate; peduncle 4--15 mm; umbels of both sexes 10--20-flowered, base thickened; bracteoles many, persistent. Male flowers: tepals not spreading, greenish yellow, outer ones cymbiform, 2.5--3 × ca. 2 mm, inner ones 2--2.5 × ca. 1 mm, thickened, abaxially concave; filaments connate, forming a short column. Female flowers: tepals 2--2.5 mm; staminodes 3. Berries dark red, globose, 6--7 mm in diam. Fl. May--Jul, fr. Dec.
Three closely allied taxa, Smilax corbularia S. hypoglauca, and S. synandra, form a natural group in SE Asia. Among them, S. synandra differs rather distinctly from the others in its partly connate tepals (rather like those of Heterosmilax), the tube of which is sometimes 4-angled. Certain intermediates blur the distinction between S. corbularia and S. hypoglauca. In addition to the key characters, the leaf blades of S. hypoglauca tend to be thinner than those of S. corbularia, and the umbels of the former species bear far fewer flowers than those of the latter. The differences among the taxa might be ecological, in which case intensive future field investigations would be necessary.
Forests, thickets; near sea level to 1600 m. Guangdong, Guangxi, Hainan, Yunnan [Indonesia, Malaysia, Myanmar, Vietnam].