Description from Flora of China
Trifolium indicum Linnaeus, Sp. Pl. 2: 765. 1753 [T. "M. indica"]; Melilotus parviflorus Desfontaines.
Annual herbs, slightly pubescent to glabrescent. Stems erect or ascending, 20-50 cm, terete, simple or branching from base. Stipules lanceolate, 4-6 mm, base auriculate, with 2 or 3 tiny teeth, margin membranous; leaflets obovate-cuneate to narrowly oblong, 10-25(-30) × 8-10 mm, appressed hairy abaxially, glabrous adaxially, lateral veins 7-9 pairs, parallel running into teeth, base cuneate, margins serrulate toward apex, apex obtuse or truncate, sometimes retuse. Racemes slender, dense, 1.5-4 cm; peduncle long; flowers 15-25; bracts filiform; pedicels ca. 1 mm. Corolla yellow, 2.2-2.8 mm; standard broadly ovate, retuse, equal to wings and keel, or sometimes keel slightly longer. Ovary narrowly ovate; ovules 2. Legume olive-green, becoming red-brown when ripe, globose, ca. 2 mm, slightly exserted from calyx, glabrous, veins reticulate. Seed 1, dark brown, broadly ovoid, ca. 1.5 mm. Fl. Mar-May, fr. May-Jun.
Open places, alkaline soil in meadows, roadsides. Anhui, Fujian, Guangdong, Guangxi, Guizhou, Hainan, Jiangsu, Sichuan, Taiwan, Yunnan, Zhejiang [S and C Asia, Europe].