Gouania leptostachya DC.

Shrubs climbing. Young branches glabrous or sparsely pilose. Leaves alternate; stipules lanceolate and caducous, or persistent and becoming a rounded, dentate bract; petiole 1-2.5 cm, sparsely or densely pilose; leaf blade abaxially pale green, adaxially dark green, ovate or ovate-oblong, 5-9 × 2.5-5 cm, papery, abaxially glabrous or sparsely hairy on veins, lateral veins 5 or 6 pairs, prominent abaxially, lower lateral veins with 3-5 secondary lateral veins, base cordate, margin crenate-serrate, apex acuminate. Flowers polygamous, 5-merous, solitary or few in fascicles and shortly pedunculate cymes, axillary cymose racemes, and terminal cymose panicles to 30 cm, pilose. Pedicel short, ca. 1 mm, glabrous or sparsely hairy. Sepals ovate-triangular, apex acuminate. Petals white, obovate, hooded, ca. as long as stamens, clawed at base. Disk distinctly pentagonous, antisepalous angles elongated into liguliform appendages. Ovary nearly completely immersed in but not fused with disk; styles short, 3-fid. Capsule 9-10(-13) mm, 1-1.2(-1.8) cm in diam., crowned by remnants of persistent calyx tube, 3-winged, dehiscing into 3 subrounded winged mericarps, wing sometimes thickened at maturity; fruiting pedicel 1-3 mm, glabrous or sparsely pilose. Seeds brownish, shiny, obovoid, ca. 1 × 3 mm. Fl. Aug-Sep, fr. Oct-Dec.

Himalaya (Kumaun to Assam), Burma, Indo-China, Malaysia.

200-2000 m

Forests, often climbing on trees, thickets; low to middle elevations. W Guangxi (Napo), Yunnan [Bhutan, India, Laos, Malaysia, Myanmar, Nepal, Philippines, Singapore, Thailand, Vietnam].

Dây gân hay còn gọi đòn kẻ cắp (danh pháp khoa học: Gouania leptostachya) là một loài thực vật có hoa trong họ Táo. Loài này được DC. mô tả khoa học đầu tiên năm 1825.

咀签（学名：Gouania leptostachya）为鼠李科咀签属下的一个种。