Description from Flora of China
Glycine abrus Linnaeus, Sp. Pl. 2: 753. 1753.
Lianas. Stem slender, much branched, sparsely white strigose. Leaves paripinnate; leaflets 8-13-paired, opposite; petiolule short; blades suboblong, 1-2 × 0.4-0.8 cm, membranous, sparsely white strigose abaxially, glabrous adaxially, rounded at base, truncate and with mucro at apex. Racemes axillary, 3-8 cm. Flowers small, dense. Calyx campanulate, 4-toothed, white strigose. Corolla purple; standard with triangular claw; wings and keels narrower. Stamens 9. Ovary hairy. Legumes oblong, 2-3.5 × 0.5-1.5 cm, leathery, dehiscent, with 2-6 seeds. Seeds lustrous, black in lower part, red in upper part, subglobose. Fl. Mar-Jun, fr. Sep-Oct.
The hard and very colorful seeds are often used in necklaces. They are dangerously toxic if ingested when the seed coat is not intact (e.g., if drilled for a necklace).
Hill forests. Guangdong, Guangxi, Taiwan, Yunnan [widespread in the tropics].