Japan Flora: Plants stoloniferous, the roots sometimes fusiform; leaves deep green, obtuse, gradually narrowed below, 7- to 11-nerved, 30-40 cm. long, 4-7 mm. wide; scapes obtusely angled, 25-40 cm. long; racemes 8-12 cm. long, many-flowered; flowers 2-5 in the axil of a bract, pale purple, the pedicels 3-6 mm. long, jointed at or above the middle, the tepals about 4 mm. long; seeds blackish. July-Sept.