22. Section Phacocystis Dumort.

(Standley, 1985, 1989)

Plants monoecious, with short- to long-creeping rhizomes, mostly forming dense clumps. Vegetative stems present (actually false stems composed nearly entirely of a series of overlapping leaf sheaths), leafy. Flowering stems erect or arched, glabrous, brownish or reddish tinged at the base. Leaves basal and on the basal half of the stems, longer than or more commonly shorter than the stems, the lowermost leaves reduced to nearly bladeless sheaths (except in C. aquatilis). Leaf blades glabrous, flat or somewhat corrugated in cross-section with the margins usually inrolled toward the tip and minutely roughened or toothed, often somewhat folded toward the base. Leaf sheaths with the ligule of various lengths, U- or V-shaped, the ventral side green or more commonly thin, papery, tinged with yellowish brown to tan and often irregularly brown- or purple-dotted, the lowermost sheaths thick, glabrous, smooth or roughened, brown or reddish tinged. Spikes 3–9 per stem, the bracts leaflike, the lowermost bract shorter than to longer than the inflorescence, lacking a sheath or nearly so. Inflorescences open to less commonly dense, the spikes all distinctly separated, 3–20 times as long as wide. Terminal 1–3 spikes staminate (sometimes pistillate toward the tip in C. crinita or with a few basal perigynia in other species) linear to narrowly oblanceolate in outline, the other lateral spikes pistillate (the uppermost pistillate spikes sometimes staminate toward the tip), 30–110 mm long, linear to narrowly oblong in outline, with numerous perigynia. Perigynia elliptic to obovate in outline, somewhat flattened and biconvex in cross-section (inflated and more or less circular in C. crinita), the ventral surface sometimes nearly flat, the tip beakless or short-beaked, the base broadly tapered, prominently 2-ribbed along the angles, otherwise variously nerved or nerveless. Styles withering during fruit development and jointed to the main body of the fruit or persistent in C. crinita. Stigmas 2. Fruits biconvex in cross-section. Seventy to 90 species, nearly worldwide.