Annual erect herb; glabrous or pubescent, lower nodes often giving out stilt roots; leaves simple, exstipulate, alternate or opposite, linear-lanceolate, narrowed into short glandular petiole, deeply serrate, acuminate; flowers irregular, showy in axillary, fascicles of 1-3 or more; pedicels glabrous; sepals 3 or 5, imbricate, anterior 2 when present minute, laterals small, green, flat, posterior one large prolonged into slender petaloid, incurved spur, others ovate-oblong; petals-3, pink, red, violet or in many colours, anterior one large, standard, orbicular, retuse, lateral wings very broad, obovate or auricled, connate, deeply notched at apex; stamens 5, anthers coherent, filaments short, broad; disk absent; ovary oblong, 5-celled, ovules many,1-seriate in each cell, stigma sessile, 5 toothed; capsule tomentose or woolly, dehiscing loculicidally, valves-5, elastically springing away from a placentiferous axis; seeds many, ellipsoid, smooth or tubercled, glabrous, narrow at both ends, exalbuminous.