Japan Flora: Resembling var. japonicum, the lower leaves broadly linear, 20-40 cm. long, 1-1.5 (-2) cm. wide; capsules narrowly obovate-oblong, to 20 mm. long. July-Sept. Woods in mountains.
Honshu (centr. distr. and westw.), Shikoku, Kyushu. Ussuri, Manchuria, and Korea.
var. parviflorum (Miq.) Hara & Mizushima. Plants 50-100 cm. high, few-leaved; lower leaves oblong to ovate- oblong, 20-30 cm. long, 6-10 cm. wide, ascending, acute, narrowed at base, the upper linear; panicles 30-50 cm. long, the lower branches ascending, rather slender, the bracts of the main axis shorter than the branches, the ultimate bracts broadly lanceolate, obtuse, 2-5 mm. long, papillose-hairy; flowers rather loosely arranged, green, 8-10 mm. wide, the pedicels 6-10 mm. long, papillose-hairy; tepals spreading to slightly reflexed, broadly oblanceolate to oblong-lanceolatc, subacute, more than twice as long as the stamens; capsules elliptic, the spreading to subreflexed tepals adnate at base. June-Aug. Woods in mountains; Hokkaido, Honshu (n. and centr. distr.). Korea.
var. japonicum (Baker) Shimizu Leaves radical and lower cauline, glabrous, narrowly oblong to linear-lanceolate, 20-35 mm. wide, gradually tapered toward the base; inflorescence 15-30 cm. long, branched, slender, the bracts shorter than the branches; flowers loosely arranged, brown-purple, about 10 mm. across, the pedicels 8-12 mm. long; tepals broadly lanceolate, subobtuse, about twice as long as the stamens; capsules elliptic, 12-15 mm. long. July-Sept. Woods in mountains. Hokkaido, Honshu.