Description from
Flora of China
Herbs perennial. Stems solitary or numerous. Leaves long petiolate, palmately lobed. Verticillasters axillary, many flowered, in spikes; bracteoles spiny, spreading or erect, shorter than calyx tube. Flowers sessile. Calyx tubular-campanulate, conspicuously 5-veined; teeth 5, broadly triangular, apex spinescent, 2 anterior teeth ± longer than posterior 3. Corolla white to yellow-white, 2-4 cm, 2-lipped; tube ca. as long as calyx tube, without hairy annulus inside; upper lip straight, galeate, densely villous outside; lower lip straight, 3-lobed; middle lobe cordate, margin membranous. Stamens 4, parallel, anterior 2 slightly longer; anthers ovoid, cells 2, transversely dehiscent, parallel. Style filiform, slightly exserted or as long as stamens, apex equally 2-cleft. Nutlets triquetrous, ovoid, apex rounded.
Two species: China, Mongolia, Russia; both in China.
Some authors have recognized to seven species, but these are connected by many transitional forms.