Japan Flora: Rhizomes rather short; stems 20-100 cm. long, with 10-20 pairs of leaves, 4-striate, sometimes de­cumbent or ascending, commonly red-brown tinged; leaves lanceolate to narrowly deltoid-ovate, 4-8 cm. long, 1-3 cm. wide, gradually acuminate, 3-nerved, green above, paler be­neath, usually sessile, papillose on margin in the upper ones, the bracts narrowly lanceolate, rather small; flowers sessile, 4.5- 6 cm. long, few to rather numerous, blue; calyx-tube 12-18 mm. long，the lobes rather unequal, linear-lanceolate; plaits of corolla deltoid, often toothed; capsules stipitate, not exserted; seeds broadly lanceolate, short-caudate at both ends. Sept.-Nov. Thickets, grassy places, and wet meadows in lowlands and low elevations in the mountains;

Honshu, Shikoku, Kyu­shu; common. Korea, Manchuria, and n. China.

f. stenophylla (Hara) Toyokuni. Narrow-leaved phase, the leaves linear to linear-lanceolate. Often growing in wet places