Rhynchosia adenodes is a perennial, prostrate herb, with a long, trailing stem, growing from a woody rootstock, 0.1–0.6 m long. The stems are decumbent, glabrous or pubescent. The leaves are trifoliate; leaflets terminal, ovate-orbicular, 6–40 × 5–30 mm, acute or obtuse, resinous dotted; petiole 5–35 mm long; stipules at right angles to the stem, ovate-lanceolate, 2–7 × 0.5–2.5 mm, glabrous. The inflorescence in axillary racemes or terminal clusters, 40–140 mm long, glabrous or pubescent. The flowers are 7–14 mm long, yellow with orange or maroon-purple venation on petals, glabrous or glandular pubescent. The fruit is a small pod, 15–18 × 4–6 mm, glabrous or glandular pubescent.

Flowering time is in spring, summer and autumn (September–June).