F. annua (Allioni) R. & S.; F. diphylla (Retz.) Vahl Annual or perennial, nearly glabrous, 5-60 cm tall; culms terete, leafy near base. Leaves linear, ca 3 mm wide, mostly arising from base of culm, the margins scabrous. Inflorescences branched, usually loose and open, subtended by few bracts, the bracts longer than inflorescence; spikelets numerous, 5-10 mm long, solitary on peduncles, acute, brownish; scales having a green keel and minute apiculum; flowers perfect; stamens 1-3; style bifid, prominently fimbriate. Achenes obovate, terete, ca 1 mm long, white to brown, with a minute projection at base, sculptured with both vertical grooves and transverse wrinkles. Croat 8566. Common in clearings. Flowers throughout the year, principally in the rainy season.