Rush-Grass, the Prickly, or LoNg-rooted, Schcenus Ma-riscus, L. a native plant, which grows in marshes, ponds, and bogs, where it flowers in themonths of July and August. - This species is injurious to cows. It frequently abounds in pools to such a degree, as to form floating islands by its interwoven roots : the stalks attain from two to six feet in height, and are principally employed as a substitute for straw in thatching houses; for which purpose they are better adapted.