Sedge (A. S. secg or soecg, a dagger, formerly applied to sharp-pointed plants in general which grew in marshes), a name for plants of the genus carex, but sometimes applied in a general way to other plants of the cyperaceoe, or sedge family, to which it belongs. There are about 200 species of the genus carex in North America; they are found in great abundance in wet places (though some are met with only in dry localities and on the tops of mountains), where they form a large portion of the vegetation, and are often mistaken for grasses, from which they differ in several important particulars. The sedges are perennial, and, especially those in wet localities, often form dense tufts or tussocks; the culms or stems are triangular and solid; the leaves are grasslike, often rough on the margin and keel, with the sheaths (which in grasses are generally split down on one side) quite closed or entire; at the upper portion of the stem are leafy or scale-like bracts, in the axils of which are borne the flower spikes, which are also terminal.
The stamens and pistils are in separate flowers, either on the same spike (androgynous), or on separate spikes on the same plant (monoecious), or rarely on distinct plants (dioecious). Both kinds of flowers are subtended by a scale-like bract, and these scales overlap one another equally around the axis to form a more or less cylindrical (sometimes ovoid) spike. The staminate flowers consist of three (rarely two) stamens to each bract; the pis-tillates have a single ovary and two or three long stigmas; the ovary is enclosed in a bag or sac with a narrow orifice from which the styles are protruded; this bag (perigynium) increases with the ripening fruit, and in some species becomes large and bladdery; the fruit is a lens-shaped, plano-convex or triangular akene. The carices vary in height from a few inches to 3 ft. and over; in some the stems are weak and thread-like, and in others very wiry and rigid; they for the most part flower early in spring, and perfect their fruit during the summer. It is estimated that there are in all about 1,000 species, which are more abundant in arctic and cold countries, and diminish toward the tropics, where they are found only in the mountainous portions.
While the species are numerous, the number of individuals is also very great, and in many places they form a large share of the vegetation; but they are of little direct value to man; their stems and foliage are dry and harsh, and contain very little sugar or starch; their chief office is to furnish mould for the sustenance of other plants. They can hardly be regarded as weeds, though some make their appearance in pastures which are too wet for the growth of nutritious grasses; the large tussocks which the sportsman and botanist uses as "stepping stones" in crossing swamps are mostly produced by C. striata, in some of its several forms. - The sand sedge (C. arena-ria), common on the shores of Europe, has a slender but strong running and branching root stock, several feet long, which serves to bind the sands where it grows naturally, and is planted for the same purpose upon the dikes in Holland; the roots of this species have a reputation for diuretic and sudorific properties, and are known in Europe as German sarsa-parilla. The Laplanders are said to convert the leaves of C. sylvatica, by drying and carding, into a sort of vegetable wool, which they use as a non-conductor of heat, to stuff their winter shoes.
In some localities carices form a considerable part of the marsh hay which is cut for use as a mulch, and for bedding animals in the stable; when saturated with urine, it is thrown upon the manure heap and soon converted into a fertilizer. The carices, though regarded by novices in botany as difficult, have been favorite objects of study by some of the most eminent botanists. An important monograph on the American species was published by Schweinitz and Torrey in the "Annals of the New York Lyceum of Natural History" in 1824; later the species of the northern states were elaborated for Gray's "Manual of Botany" by John Carey; numerous papers on the genus by the late Dr. Chester Dewey are to be found running through the "American Journal of Science," in which the number of species is increased to an extent not accepted by other botanists; and Mr. S. T. Olney of Rhode Island has made important contributions to our knowledge of these plants. One of the finest monographs upon any specialty in botany is the "Illustrations of the Genus Carex," by Francis Boot (4 vols, fol., London, 1858-'67), with 600 plates.
A Sedge (Carex umbellata), with separate Perigonium and Bract, Pistil, and section of Ovary.