Japan Flora: Slender perennial with tuberous roots; stems erect, 4Q-70 cm. long, with few leaves on the lower part; leaves linear, 5-15 cm. rarely to 20 cm. long, 3-6 mm. wide, gradually narrowed at tip, sheathing at base, the upper scalelike leaves few, erect, linear, broadened at base; spike rather densely flowered, the bracts narrowly ovate, 8-15 mm. long, abruptly narrowed at tip; flowers rather numerous, greenish, 8-10 mm. across; sepals unequal, the dorsal rounded- cordate, 3-4 mm. long, 5-nerved, the lateral sepals prominently oblique, subreniform, 6-7 mm. long and as wide, strongly reflexed; petals subdeltoid, much dilated on lower margins, as long as the dorsal sepal, the anterior margin appressed to the column; lip about 2 cm. long, 3-lobed, the lobes linear, the lateral lobes obliquely spreading, about 10 mm. long, sometimes obsoletely toothed, the terminal lobe about 15 mm. long, entire; spur about 15 mm. long, slender, with an abruptly inflated apex, nearly as long as to slightly shorter than the ovary. July-Sept. Bogs and wet grassy places in lowlands;

Hokkaido, Honshu, Shikoku, Kyushu.