落地豆 luo di dou

Trigonella indica Linnaeus, Sp. Pl. 2: 778. 1753; Dill­wynia trifoliata Roth; Rothia trifoliata (Roth) Persoon; Wes­tonia humifusa Sprengel, nom. illeg. superfl.; W. indica (Lin­naeus) Kuntze.

Herbs, annual, ascending, to 25 cm. Stems adpressed-pi­lose. Stipules lanceolate, ca. 4 × 1.5 mm. Petiole ca. 7 mm; petiolules to 1 mm; leaflet blades oblanceolate, 1-2.2 × 0.4-0.8 cm, both surfaces adpressed pilose, base cuneate, apex rounded to broadly acute. Inflorescences leaf-opposed or extra-axillary, 1-3-flowered, congested; bracts filiform, ca. 1.5 mm; peduncle 0-2.5 mm. Pedicel ca. 1.5 mm. Calyx obconical, 4-6 mm, divi­ded to slightly below middle; lobes triangular, apex acuminate. Corolla yellow, exserted from calyx; standard oblong-orbicular, 5.5-6.5 mm, abaxially pilose along midline; wings oblong, slightly shorter than standard; keel ± as long as standard. Leg­ume narrowly oblong, 3.5-5.5 × ca. 0.2 cm, straight, slightly compressed, more than 20-seeded, adpressed pubescent. Seeds brown, D-shaped, ca. 1.3 mm, smooth. Fl. and fr. Mar-Jun.

Sandy areas; near sea level. Guangdong, Hainan [India, Indonesia, Laos, Malaysia, Sri Lanka, Thailand, Vietnam; N Australia].