sedge (Cyperaceae)
Figure 1. Pendulous sedge grows in large clumps in damp, shady woods while sea club-rush is a plnt of salt marshes. Papyrus, from which an ancient writing material was made, is a member of the same family.
The sedges (family Cyperaceae) are a widespread group of plants usually found in waterlogged acid soils. Although found worldwide, they prefer colder, wetter regions than grasses. The family is large, with about 90 genera and 5,500 species known. The largest genus is the "true sedges", Carex, with over 2,000 identified species.
Some species superficially resemble the closely related rushes and the more distantly related grasses. Features distinguishing members of the sedge family from grasses or rushes are stems with triangular cross-sections (with occasional exceptions) and leaves that are spirally arranged in three ranks. In comparison, grasses have alternate leaves, forming two ranks.
