Trifolium subterraneum

Prostrate or decumbent annual herb; stems few, 10–35 cm long, weak, sparingly branched or unbranched, sparsely hairy to glabrescent. Leaves palmately trifoliolate, long-petiolate; leaflets obovate to obcordate, 8–25 mm long, 8–25 mm wide, appressed-hairy on both surfaces, apex notched, upper margins minutely dentate; stipules leafy. Inflorescence with 3–6 fertile flowers and several sterile flowers developing later, axillary, obovoid, becoming globose, c. 15 mm long, c. 5 mm wide, pedunculate; flowers sessile. Fertile calyx 3–4 mm long, glabrous or sparsely pubescent, tube cylindric, many-veined, sometimes red-tipped, distended in fruit, throat open, glabrous, teeth almost as long as tube, subequal, blunt, recurved in pod; sterile calyx with solid, stalk-like tube, teeth linear; corolla 8–14 mm long, white with pink stripes, not persistent; standard elliptic. Fruiting heads globose, c. 10 mm long, 10 mm wide, pushed into the ground by a few seed-bearing calyces and many deflexed sterile ones; pod ovoid to obovoid, c. 3 mm long, somewhat exserted from split calyx tube; seed 1, ovoid, c. 3 mm long, black. Flowers mainly Sep.–Jan.