THE SEDGE FAMILY (Cyperaceae)

The Cyperaceae are a family of monocotyledonous flowering plants known as sedges, which superficially resemble grasses or rushes. The family is large, with some 5,500 species described in about 109 genera. These species are widely distributed, with the centres of diversity occurring in tropical Asia and tropical South America. While sedges may be found growing in almost all environments, many are associated with wetlands, or with poor soils. Ecological communities dominated by sedges are known as sedgelands.

Some well-known sedges include the water chestnut (Eleocharis dulcis), (the ‘chestnut’ is in fact a storage organ called a corm on an underwater stem) and the papyrus sedge (Cyperus papyrus), from which the Ancient Egyptian writing material was made. This family also includes cotton-grass (Eriophorum), spike-rush (Eleocharis), sawgrass (Cladium), nutsedge or nutgrass (Cyperus rotundus, a common lawn weed), the large genus of Carex, and white star sedge (Rhynchospora colorata).

(One particular famous story involving bulrushes is that of the Ark of bulrushes. In this story, it is said that the infant Moses was found in a boat made of bulrushes. Within the context of the story, this is probably paper reed, Cyperus papyrus.)

The stems of sedges (with occasional exceptions) are not hollow, have triangular cross-sections and no thickened nodes, features that distinguish them from grasses or rushes. Leaves are parallel-veined and narrow (grass-like), spirally arranged in three ranks (grasses have alternate leaves forming two ranks).

Flowers are, typically for wind pollinated plants, small and inconspicuous. They are either bi- or uni-sexual and in the latter case, the single sex flowers may be carried on the same or on different plants. They are radially symmetrical, carried singly or in clusters, spikes or heads, flower parts usually in 3’s and the sepals and petals reduced to hairs or scales. Fruits may be nutty or with abundant hairs as in cotton grass.

(source: Wikipedia)