Japan Flora: Thinly pubescent or nearly glabrous short-rhizomatous perennial; stems erect, rather stout, 30-50 cm. long; leaves membranous, ovate to broadly so, 6-10 cm. long, 4-6 cm. wide, acute, rounded to shallowly cordate at base, acutely incised and toothed, the peti­oles 3-5 cm. long; verticils often loosely arranged in the lower ones, becoming capitate and spicate above, the bracts broadly lanceolate, slightly longer than the calyx; calyx 5-fid, glabres- cent, the lobes lanceolate; corolla dark blue-purple, the tube about 20 mm. long, ampliate above, the limb rather small, the upper lip short, broad, 2-Iobed; nutlets obovate-oblong, 2.5 mm. long. May-June. Damp woods along streams.

Hon­shu (Kanto and centr. distr.).