Cyperus esculentus L.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Sweet-scented perennial with numerous slender rhizomes ending in small tubers; stems stout, triquetrous, 1–7 dm, smooth; lvs basally disposed, elongate, 3–8 mm wide; at least the lower invol bracts surpassing the infl; rays usually several, to 7 cm but more often not surpassing the sessile spikes, often again branched at the top; prophyll obliquely truncate or prolonged 1–3 mm beyond the orifice; spikes numerous in short-cylindric spikes, slender, 0.5–5 cm, only 1–2 mm wide, with 8–30+ fls; scales yellow-brown, (2–)2.5–3(–3.5) mm, thin, scarcely keeled, ovate, acute, conspicuously 7–9-nerved; rachilla persistent, narrowly hyaline-winged; achenes oblong, unequally trigonous, 1.3–2 mm, tan to golden-brown; 2n=108. Damp or wet soil, sometimes a weed; widespread in trop. and temp. (but not cold-temp.) regions, and nearly throughout our range.