型態特徵

Erect, glabrous herbs. Leaves alternate, lanceolate-elliptic or elliptic, the apex acuminate, the base cuneate-obtuse or attenuate, the margins serrate or crenate, glabrous or hairy, petiolate; stipules absent. Flowers zygomorphic, bisexual, terminal or axillary, solitary or racemous, yellow, pale purple, reddishpurple or white; sepals 3, the 2 lateral ones small, the lip saccate, the sac with a linear, straight or recurved spur; petals 3, the standard often apiculate, the lateral wings often 2–3-lobed; stamens 5, monadelphous; ovary linear, with a short style. Capsules loculicidally dehiscent.