Gleditsia microcarpa F. P. Metcalf.

Trees, 3-20 m tall. Branches brownish gray, with robust spines. Spines brownish purple, conical, 3-5 cm, branched. Leaves pinnate or bipinnate (pinnae 2-6 pairs), 10-18 cm; petiolules ca. 1 mm; leaflets 5-9 pairs, adaxially shiny, obliquely elliptic to rhombic-oblong, 2.5-4 × 1-2 cm, papery to thinly leathery, abaxially glabrous, adaxially slightly puberulent on veins, reticulate veinlets slightly lax, obscure, base obliquely acute or obliquely cuneate, margin obtusely serrate or subentire, apex rounded, often emarginate. Flowers polygamous, pale green or greenish white; pedicels 1-2.5 mm. Male flowers: 4-5 mm in diam., several fascicled or in cymules, cymules in dense racemes again, several racemes comprising a panicle to 28 cm, puberulent, axillary or terminal; sepals 5, lanceolate, ca. as long as receptacle, outside densely puberulent; petals 5, elliptic, ca. 2 mm, outside densely puberulent, inside pubescent. Bisexual flowers: 7-9 mm in diam.; inflorescence as male inflorescence, with scattered flowers; calyx tube ca. 2 mm, glabrous; calyx lobes 5 or 6, lanceolate, ca. 3 mm, outside puberulent, inside as petals densely light brown crisped pubescent; petals 5 or 6, elliptic, outside velutinous. Stamens 5, not exserted. Ovary ses­sile, densely light brown silky. Legume subsessile, brownish black when dry, compressed, strap-shaped, (4-)6-12 × 1-2.5 cm, straight or slightly curved, valve leathery, conspicuously swollen opposite seeds, apex mucronate. Seeds 5-12, deep brown to brownish black, slightly compressed, elliptic to ob­long, 7-11 × 4-5 mm, smooth. Fl. Jun-Oct, fr. Nov-Apr.

Gentle slopes, mountain valleys, forests, near roads, by streams, sunny places. Guangdong, Guangxi [Vietnam].