* Flowers yellow.
O. campestris: stem short, tufted, scarcely lengthening into shortly ascending branches; leaflets 10-15 pairs, with an odd one, oblong or lanceolate, hairy; flowers in short spikes, pale yellow tinged with purple; calyx hairy; pod erect, ovoid, covered with short, usually black, hairs. - Clova mountains, rare. Fl. July.
** Flowers purple. O. uralensis: stem short; the foliage, inflorescence, and pod as in the last, but more densely covered with soft, silky hairs; flowers bright purple. - Dry hilly pastures in Scotland. Fl. July.