Cyperaceae (Sedge Family)
A large family resembling grasses or rushes, usually spreading from rhizomes. Stems are solid (or rarely hollow) and mostly triangular, less commonly round. Leaves are parallel-veined, mostly three-ranked, with grass-like blades, or blades may be reduced or lacking. Inflorescence is in spikes or spikelets; flowers are very small and perfect, but some plants are dioecious. The perianth consists of one to six short or elongate bristles, or none; there are one to three stamens; the ovary is one-celled; the fruit is an achene. The species are numerous and difficult to identify, so they are not described individually; only the common genera are shown here.
Carex.Sedge. Common grasslike perennials with three-ranked leaves, closed sheaths, and solid stems. Floral spikes are in various forms and may be unisexual. Each is usually subtended by a bract, large and leafy, or much reduced and inconspicuous. There are three stamens, or less commonly two; pistillate flowers are enclosed by a saclike scale called a perigynium, as well as being subtended by an open scale; there are two or three stigmas with the achene accordingly lenticular or three-sided. This is the largest genus in the family by far and is represented in the range by about 30 species.
Eliocharis.Spikebrush. Stems round or flattened; leaves broad, reduced to mere sheaths or scales; spikelets solitary and terminal without subtending bracts; flowers perfect; perianth has zero to six (or nine) bristles; three stamens. The thickened base of the style persists as a tubercle at the apex of the achene. Members of this genus are relatively slender and dainty. Only four species are known in the range.
Scirpus.Bulrush. Stems mostly solid and triangular (except S. acutus ); leaves long and grasslike or much reduced; inflorescence in various forms, subtended by one or more large and leafy or small bracts; flowers perfect, in the axils of the scales; perianth of one to six bristles; three stamens; style bifid or trifid; achene accordingly lenticular or three-sided, lacking a tubercle at the apex. Members of this genus are comparatively coarse. Only four species are known in the range.