RESTIONACEAE  

Plants caespitose or rhizomatous. Culms widely spaced, erect, simple or branching, terete or compressed, often with shorter sterile stems. Leaf sheaths closely convolute or sometimes loose in their upper parts, persistent or caducous. Maleinflorescence usually similar or identical to female; perianth segments woody; florets often somewhat smaller than female. Male spikelets many, in panicled cymes, or fewer in spicate cymes, or solitary and terminal, with many florets; perianth compressed; segments 6, outer lateral ones usually boat-shaped, villous on midrib or glabrous; ovary rudimentary. Femaleinflorescence generally of large numbers of compact spikelets clustered at several fertile nodes, these often obscured by large persistent spathes. Femalespikelets poorly organised, with 1-many florets; bracts usually shorter than florets; perianth subtrigonous; perianth segments osseous, often black, outer lateral ones not keeled; staminodes minute or 0; ovary usually trigonous, rarely compressed, 1-locular; styles 2 or 3, short, plumose, free or connate below middle. Fruit a trigonous nutlet.

Plants caespitose or with long or short rhizomes. Culms usually simple, branching only in 1 species ( C. microcarpum (Kunth) Pillans). Leaf sheaths caducous or semipersistent if culms are branching. Maleinflorescence of many small, poorly defined spikelets aggregated at several fertile nodes, overtopped by caducous spathes. Malespikelets with few to many florets, usually somewhat compressed, with few to 0 sterile bracts; perianth +/- trigonous or compressed, often somewhat arcuate, usually much longer than subtending bract; segments 6, in 2 whorls, outer lateral ones boat-shaped, mostly keeled, glabrous or villous on keel, inner oblong or lanceolate, dorsally rounded; anthers ovate-oblong, with a prominent apiculus; ovary rudimentary. Femaleinflorescence resembling male. Femalespikelets resembling male, generally fewer and more crowded; perianth trigonous or compressed; perianth segments osseous, often black, subequal or inner longer than outer, outer segments not keeled; staminodes well developed, strap-shaped; ovary trigonous, 3-lobed or compressed 3-locular; styles 3, free, plumose. Fruit a dehiscent 1-3-seeded capsule. Seeds highly ornamented.

Plants caespitose, rarely mat-forming. Rhizomes short or long. Culms simple or branching. Leaf sheaths closely convolute. Maleinflorescence of many small spherical to elliptical spikelets; spathes caducous. Malespikelets: bracts small, taller than florets, cartilaginous; anthers exserted at anthesis. Femaleinflorescence of (1-)several spikelets; spathes similar to sheaths, persistent. Femalespikelets: bracts bony, tightly convolute into spindle-shaped spikelets, with 2 or 3 bracts fertile; perianth segments 6, subequal, hyaline, small to minute; ovary 1-locular; styles 2, free to base, plumose, slightly longer to much longer than ovary. Fruit a shiny, adaxially flattened, black nutlet with an elaiosome.

Plants tightly caespitose. Rhizomes usually very short. Culms simple. Leafsheaths caducous. Maleinflorescence very similar to female. Malespikelets: florets sometimes smaller than female ones; pollen released inside perianth segments. Female inflorescence of many elongated, poorly defined spikelets clustered at several fertile nodes; spathellae and bracts taller than florets, hyaline and soon lacerate, persisting as hairs around maturing florets; spathes taller or smaller than spikelets, papery to cartilaginous. Female spikelets: perianth segments osseous, usually acute, backs all rounded, inner segments usually longer than outer ones; staminodes well developed; ovary 3-locular; styles 3, plumose. Fruit at least partly dehiscent.