This section is from the book "Handbook Of Hardy Trees, Shrubs, And Herbaceous Plants", by W. Botting Hemsley. Also available from Amazon: Handbook of hardy trees, shrubs, and herbaceous plants.
The Sedges are distinguished from the true Grasses by their usually angular solid not conspicuously jointed stems, and the sheath of the leaves when present is not split on one side. Leaves commonly very sharp at the edges. Anthers continuous with the filaments. Inflorescence paniculate, irregularly clustered, spicate or racemose. The greater number of the plants of this order inhabit marshy places, and their herbage being-coarse and rough is little sought after by cattle. There are upwards of 100 genera, including about 2,000 species, occurring in all parts of the world. Ten genera are' represented in Britain by about 100 species. Some of the larger-growing species are stately or elegant, and may be introduced with effect in marshy spots of the wilderness or on the margins of streams and lakes. The genus Carex, distinguished by its utriculate fruit, includes about one half of the species, some of which are amongst the most conspicuous and graceful of the hardy members of this order. They have commonly dense cylindrical eventually drooping spikes of flowers on slender stalks. C. paludosa, C. pseudo-Cyperus, and C. ripdrla are river-side species frequent in South Britain, the latter growing to a height of 5 or 6 feet in some localities. C. pendula is a common woodland species growing in dense tufts with large broad foliage and flowering stems, 5 to 7 feet, readily distinguished from all other native species by the very long (often 6 inches) and slender pendulous spikelets on long slender peduncles. C. sylvdtica is very abundant in woods and copses, and remarkable for its slender habit and pale yellowish-green herbage. A variegated variety of C. Japonica is cultivated.
The genus Scirpus has a cymose or fascicled inflorescence. S. lacustris, the Bulrush, is a conspicuous semi-aquatic species with terete spongy nearly leafless stems 8 to 10 feet high, in rich swamps. S. sylvaticus is frequently met with in damp shady situations, and is remarkable for its leafy stems and very large bracteate cymes. Eriophorum, Cotton-grass, is readily known by the oval or oblong spikes, in which the bristles are exceedingly slender and silvery. Cladium Mariscus and Cyperus longus are tall-growing rather rare indigenous plants of this order.