Sulphur clover

Trifolium ochroleucon is a herbaceous perennial of the legume family growing 20-50 cm tall from a stout woody rootstock. Stems are erect or ascending, simple or sparsely branched, and softly hairy throughout. Leaves are trifoliolate; lower leaves are long-petiolate with elliptic to oblong-elliptic leaflets 2-4 cm long, hairy on both surfaces, finely net-veined, and with entire to minutely denticulate margins. Stipules are membranous, lanceolate, and have prominent dark veins. The inflorescences are dense, ovoid to subglobose terminal heads 2-3 cm across, subtended by the uppermost pair of leaves and composed of numerous papilionaceous flowers each 15-20 mm long. The corolla is pale sulphur-yellow to cream, sometimes flushing brown as it ages, with a persistent hairy calyx whose teeth are unequal, the lowest distinctly longer than the rest. Fruits are small one- or two-seeded pods enclosed in the calyx. Found in dry calcareous grasslands and meadows of central and southern Europe, it flowers in June and July.