Trifolium dubium

Prostrate or ascending annual herb; stems 5–40 cm long, branching, sparsely hairy to glabrous. Leaves pinnately trifoliolate, short-petiolate; leaflets obovate, 4–13 mm long, 4–8 mm wide, virtually glabrous, finely toothed, apex rounded or retuse; stipules leafy, adnate to base of petioles. Inflorescence 3–20-flowered, axillary, hemispherical, 6–7 mm long, 8–9 mm wide, pedunculate; flowers subsessile. Calyx 1.5–2 mm long, glabrous, tube campanulate, 5-veined, throat open, teeth unequal, spiny, erect in fruit, lower 3 teeth almost twice as long as tube, upper teeth shorter than tube; corolla 3–4 mm long, yellow, persistent; standard ovate, conduplicate, margins entire or obscurely dentate. Pod globose, c. 2 mm long, included in calyx tube; seed 1, ovoid, c. 1 mm long, brownish. Flowers mainly Sep.–Jan.