Cyperaceae

Abstract

Small to tall perennial or annual herbs, rarely dwarf shrubs, shrubs, or lianas, terrestrial or helophytic, rarely aquatic, epiphytic, or epilithic; the perennial species tufted, rhizomatous, stoloniferous, bulbiferous, more rarely with a caudex. Cu/ms central, more rarely lateral, scapose or 1few-noded, more rarely many-noded, base sometimes bulbously thickened, (sub)trigonous to (sub)terete in cross-section, more rarely compressed, winged or 4–5–6-angular, rarely hollow or septate, smooth or scabrid, rarely viscid, papillose, or hairy. Leaves all (sub)basal or 1-few cauline, rarely all cauline, (spiro)tristichous, more rarely (spiro)distichous, lower leaves often (rarely all leaves) reduced to a sheath; sheaths usually closed, very rarely open, sometimes succulent or spongy; ligule present or absent, contraligule rarely developed; blade linear, rarely oblong, ensiform or terete, rarely pseudopetiolate. Inflorescence terminal, more rarely pseudolateral, paniculate, corymbose, spicate, anthelate, or capitate (often in combinations), more rarely reduced to a single spikelet, open or (partly) condensed, with few to many spikelets, branching from the axil of normal bracts, rarely from the axil of prophylls; prophylls present or absent; bracts leaflike or not, sheathing or not, lower primary bract sometimes culmlike and erect, spikelet bracts often small and glumelike. Spikelets with 1-many glumes, in cross-section rounded, 4–5-angular, laterally or rarely dorsiventrally compressed. Rachilla persistent or deciduous, rarely disarticulating into 1-flowered parts, rachilla internodes short or elongated, sometimes winged, or thickened and curved round the ripening fruit(s). Lateral spikelets usually prophyllate (with a basal, 2-keeled, usually empty glume), this prophyll rarely fertile, rarely utriculiform, and then enclosing the rachilla and its own flower. Glumes spirally arranged or distichous, rarely pentastichous, all glumes (sub)similar or of increasing length towards the (often upper) female or bisexual flowers, deciduous or persistent; all glumes fertile (often except for the lowermost and uppermost glumes), or only 1 to few upper (larger) glumes fertile, and then flower often enclosed by the wings of the next glume. Flowers bisexual or (functionally) unisexual, and then spikelets bisexual or unisexual, rarely dioecious. Hypogynous scales 0-(1-)3–6(-many), often bristle-like and retrorsely scabrid, more rarely laminar, sometimes with highly elaborated forms, shorter or longer than the fruit, usually deciduous with the fruit, rarely persistent on the rachilla. Stamens usually 3 (1 medio-anterior, 2 lateral), but not rarely reduced to 1 or 2, or 4–6 and even more numerouso; filaments sometimes strongly elongating after anthesis, rarely connate; anther basifixed, introrse, elliptic or oblong to linear, base often ± sagittate, connective often developed into a ± pronounced crest. Pistil superior, usually 3-carpellate, unilocular, ± trigonous, with 1 medio-anterior rib and 2 lateral ribs; style long, more rarely short, with 3 stigmatic branches, these sometimes with particular papillae; pistil sometimes 2-carpellate, and then either dorsiventrally or more rarely laterally compressed, rarely with a more elevated number of stigmatic branches. Style base distinct from the ovary or not, often conspicuously thickened and persistent, glabrous, scabrid, or variously hairy. Ovule single, basal, anatropous. Fruit an achene s.l. (nutlet), rarely drupaceous, usually ovate, elliptic, or obovate in outline, and (sub)trigonous to (dorsiventrally or, more rarely, laterally) lenticular in cross-section, surface smooth, punctate, reticulate or rugose, sometimes extremely differentiated, glabrous or finely hairy, sometimes seated on different types of cuplike structures. Seed with thin testa, free from the fruit wall, raphe and chalaza usually conspicuous, embryo small, basal, surrounded by abundant mealy or oily endosperm.