O. sativa: stems ascending, 1-2 feet long; stipules brown, finely pointed; leaflets numerous, oblong, glabrous above; peduncles longer than the leaves, bearing a spike of pale pink flowers, at first closely packed, but afterwards lengthening out; pod twice as long as the calyx, the upper edge nearly straight, the lower semicircular,bordered with short, sometimes prickly teeth. - Limestone districts, cultivated for forage. Fl. June, July.