Japan Flora: Rhizomes very short or nearly absent; culms 15-50 cm. long, compressed, glabrous or hairy; leaves flat, 1.5-5 mm. wide, abruptly acute, hairy, rarely nearly glabrous, the sheath frequently hairy; inflores­cence umbelliform, compound, usually somewhat hairy, the lowest bract linear, longer or shorter than the inflorescence; spikelets usually rather numerous, ovoid or narrowly so, 5-8 mm. long, 2.5-3 mm. thick, terete, acute, sessile or short- peduncled, fulvous to tawny, frequently somewhat reddish brown, lustrous; scales ovate-orbicular, 2-3 mm. long, obtuse and often short-mucronate, not keeled, glabrous; achenes broadly obovate, 0.8-1.2 mm. long, biconvex, light yellow, with elevated, transversely oblong reticulations; stamens 2 or 3, the anthers 0.5-0.8 mm. long.  Rather wet places in low­ lands; Hokkaido, Honshu, Shikoku, Kyushu; in all warmer regions of the world. Very common and widely variable, the following forms noted from this area.                   

f. floribunda (Miq.) Ohwi.  Robust; spikelets numerous; culms slighdy thickened at base; nearly glabrous throughout. 

f. tomentosa (Vahl) Ohwi. Leaf-sheatlis densely to­mentose, otherwise as in F. floribunda.

f. depauperata (C. B. Clarke) Ohwi. Slender; leaves fili­form; spikelets few, usually 1 or 2.

var. tashiroana (Ohwi) Ohwi. Leaves 1-2 mm. wide, glabrous; spike­lets narrow, 8-15 mm. long, the lateral ones on long peduncles 2-7 cm. long; scales oblong, 4 mm. long; achenes obovate- deltoid; anthers 1.2-1.8 mm. long. Aug.-Oct. Near moun­tain hot springs;  Kyushu.     

f. cincta (Ohwi) Ohwi.  Leaves hairy, 2-3 mm. wide.