Description from Flora of China
Shrubs or annual or biennial herbs. Leaves petiolate; blade margin dentate. Verticillasters 2-8-flowered; bracts shorter than calyx, linear, early deciduous. Calyx campanulate, hairy outside, glabrous except for hairy teeth inside, 5-veined; teeth 5, lanceolate, posterior 3 slightly larger than anterior 2. Corolla purple-red or reddish, 1.5-2 × as long as calyx, 2-lipped, hairy especially on upper lip outside; tube slightly exserted, hairy annulate inside; upper lip straight, oblong, rarely obovate, emarginate, rarely as long as tube; lower lip spreading, 3-lobed, middle lobe obcordate to obovate, lateral lobes subcircular to ovate. Stamens 4, anterior 2 longer; anthers ovoid, cells 2, divaricate. Ovary lobes truncate, glabrous or rarely minutely hispid at apex. Style apex subequally 2-cleft. Nutlets triquetrous, oblong, obovoid, to obconical, base attenuate, apex subtruncate, glabrous or short hairy.
About six species: one in Europe and SW Asia, five in China, among them one also in Japan.
Galeobdolon is often included in Lamium.