Japan Flora: Rhizomes slender, creeping; stems erect, 20-40 cm. long, prominently white-pilose; leaves loosely few-paired, deltoid-cordate to broadly ovate, obtuse, cordate at base, obtusely toothed, spread­ing-hairy, often prominently pubescent on both sides, the peti­oles 5-20 mm. long, the upper leaves sometimes orbicular, 1-2.5 cm. in diameter; spikes 3-8 cm. long, with prominent spreading hairs; calyx about 3 mm. long in anthesis, 6-7 mm. long in fruit; corolla 18*22 mm. long, geniculate at the base, becoming erect above, pale purple; nutlets about 1 mm. long, densely mammillate. May-June. Sunny hills; Honshu, Shikoku, Kyushu; common. Korea, China, Indochina, For­mosa, and Ryukyus. 

var. parvifolia (Makino) Makino. Stems shorter, 5-20 cm. long, long-decumbent at base; leaves small, usually about 1 cm. long and as wide, more sparsely toothed. Apr.-June. Honshu (centr. and w. distr.), Shikoku, Kyushu.

var. tsusimensis (H.Hara) Ohwi. Plant rather large, 10-30 cm. high; leaves 2-4 cm. long and as wide, shallowly cordate to truncate at base, with impressed nerves above. Honshu (w. distr.), Kyushu. Korea.