CYPERACEAE  

Annuals or perennials, tufted or long-rhizomatous. Culms with basal nodes. Leaves mainly basal, sometimes cauline, ligulate or eligulate; sheath with adaxial apex truncate or n-shaped; blade linear, sometimes short, with or without keeled midrib, profile V-shaped, occasionally crescentiform. Inflorescence sometimes pseudolateral, mostly anthelate, sometimes capitate or paniculate. Spikelets of many distichous glumes, 2 lowest glumes empty, upper several to many bisexual, fertile, uppermost with male florets or empty; rachilla persistent, wingless. Perianth 0. Stamens 2 or 3. Style slender, 2-branched. Nutlet oblong or ellipsoid, laterally compressed (i.e. with edge of nutlet facing rachilla), smooth, papillose or rugose. x = 10 (12) (aneuploids, high polyploidy).

Aquatic long-stoloniferous perennials. Culms with basal nodes, 3-angled. Leaves basal, ligulate; sheath with conspicuous venation, adaxial apex V-shaped; blade flat with keeled midrib, profile V-shaped. Inflorescence anthelate; subtending bracts spreading. Spikes +/- globose. Spikelets many, dense; glumes spirally arranged. Perianth 0. Stamens 3. Style base persistent, branches 2. Nutlet +/- ovoid, sessile, with corky tissue enveloping base.

Annuals or perennials, tufted, small or moderately robust. Culms erect, terete, glabrous, with basal nodes. Leaves basal, eligulate, glabrous; sheath short, with adaxial apex truncate; blade with or without keeled midrib, profile V-shaped or crescentiform. Inflorescence capitate, of 1-20 sessile spikes; subtending bracts 2-few, erect or spreading. Spikes ovoid, axes elongated; spikelet bracts many, spirally arranged, lowermost and uppermost frequently empty. Spikelets comprising an adaxial prophyll, with frequently 2 minute hyaline scales and a 1-flowered floret subtended by a glume; florets mostly bisexual, fertile, uppermost male or absent. Perianth 0. Stamens 1-3. Style linear or 0, branches 2 or 3, short, not dilated at base, deciduous. Nutlet narrowly oblong to broadly obovate to circular to 3-angled, papillate. x = 13 (8, 19, 23, 29) (aneuploids, polyploidy).

Mainly perennials, tufted or long-rhizomatous, frequently lemon-scented. Culms with basal nodes. Leaves basal, eligulate; sheath with adaxial apex truncate; blade linear with keeled midrib, profile V-shaped. Inflorescence capitate, of 1-3 sessile spikes, sometimes proliferous; subtending bracts 3-6. Spikes ovoid or cylindric, dense. Spikelets many, of 4-7 distichous glumes, lowest 1 or 2 glumes empty, next 1 or 2 with bisexual, fertile florets, upper ones with male florets or empty; rachilla wingless, caducous by disarticulation from a cushion below lowest fertile floret. Perianth 0. Stamens 1-3. Style slender, 2-branched. Nutlet black or brown, ellipsoid or oblong, laterally compressed (i.e. with edge facing rachilla), smooth. x = 6, 8 (7, 9) (polyploidy).

Perennials, tufted. Culms erect, with basal nodes, terete. Leaves eligulate; sheath split to base; blade short or 0, without keeled midrib, profile thickly crescentiform. Inflorescence capitate; subtending bracts erect. Spikes 1-10, ellipsoid-cylindric, obtuse. Spikelets elliptical to lanceolate, dorsiventrally compressed. Perianth 0. Stamens 3. Style short; branches 3, long. Nutlet grey or black, obovoid, flattened, minutely papillose, falling with filaments.