Description from Flora of China
Herbs annual, biennial, or perennial, erect. Leaves 3-7-lobed, basal ± palmately lobed, usually deciduous at anthesis; stem leaves entire, incised, or 3-lobed. Verticillasters many flowered, in long spikes; bracteoles subulate or spinescent, rigid or flaccid. Calyx obconical or tubular-campanulate, 5-veined, obscurely 2-lipped; upper lip straight, 3-toothed; lower lip 2-toothed, teeth coalescent, spreading or slightly spreading. Corolla white, reddish, to purplish, 2-lipped, tube exserted; upper lip oblong, obovate, or ovate-orbicular, margin entire, straight, villous or glabrous; lower lip straight or spreading, spotted, 3-lobed, lobes oblong-ovate or middle lobe shallowly cordate, larger than ovate lateral lobes. Stamens 4, anterior 2 longer, posterior 2 parallel; anther cells 2, parallel. Style apex equally 2-cleft, lobes subulate. Nutlets acutely triquetrous, base cuneate, apex truncate.
About 20 species: Africa, Asia, Europe, North America, South America; 12 species in China.