Japan Flora: culms 20-40 cm. long; leaf-blades 2-4 mm. wide; spikes 2-4, die pistillate globose to oblong, usually sessile, 7-12 mm. long, erect; perigynia much longer than the scales, 3 mm. long, spreading, ellipsoidal, spongy-membranous, pale, strongly inflated, abruptly short-beaked; stigmas short, deciduous after anthesis. Apr-June. Woods on hillsides and in lowlands.