Japan Flora: More or less long-pubescent stoloniferous green herb; flower­ing stems erect, 15-30 cm. long, with few pairs of leaves; cauline leaves thinly membranous, deltoid-cordate to ovate- cordate, 2-5 cm. long, 2-3.5 cm. wide, acute, coarsely obtuse­toothed, the petioles 2-5 cm. long; leaves of the stolons to 10 cm. long; flowers 3-12, in loose terminal one-sided spikes, the bracts broadly ovate, 7-15 mm. long, the pedicels and some­times also the floral axis minutely puberulent; calyx about 1 cm. long; corolla purple-blue, 4-5 cm. long, the upper lip sub­erect, 8-30 mm. long, the lower lip with a larger, obcordate, retuse median lobe and with spreading, dark-spotted lateral lobes; nutlets narrowly obovate, about 3 mm. long, loosely puberulent. Apr.-May. Damp woods in mountains.

Hon­shu, Shikoku, Kyushu. Manchuria and Korea.