Chaenostoma

Subshrubs or perennial or rarely annual herbs, mostly glandular, occasionally aromatic or foetid. Leaves usually opposite, sometimes alternate upwards, entire or toothed, rarely more deeply lobed, sessile, sometimes decurrent in wings or ridges along stem. Inflorescence a racemose, a cymose raceme or paniculate, bracteate; bracts adnate to base of pedicel. Calyx bilabiate, upper lip 2-lobed, lower lip 3-lobed, or rarely regularly divided into 6–9 lobes; corolla 5-lobed, tube cylindrical or funnel-shaped; stamens 4, rarely 5, in pairs of unequal length, filaments usually inserted in upper part of corolla tube; stigma with 2 marginal bands of papillae. Capsule septicidal, glabrous; seeds elliptic.