Brassicaceæ

pl. ( Bot. ) An order of plants, alliance Cistales. DIAG. Tetramerous flowers and tetradynamous stamens. They are herbaceous plants, annual, biennial, or perennial, very seldom suffruticose. Leaves alternate. Flowers usually yellow or white, without bracts, generally in racemes; sepals 4, deciduous, imbricate or valvate; petals 4, cruciate, alternate with the sepals; stamens 6, of which 2 are shorter; disk with various green glands between the petals and the stamens and ovary; ovary superior, unilocular; stigmas 2, opposite the placente; fruit a silique or silicule; seeds attached in a single row by a funiculus to each side of the placente; albumen none. - Properties. The Bra icaceæ as a cla are of much importance to man. They furnish several alimentary articles which are very nutritious, as the turnip, cabbage, cauliflower; several others are used as condiments; as mustard, radish, cochlear i a, . They all po e a peculiar acrid, volatile principle, dispersed through every part, often accompanied by an ethereal oil abounding in sulphur. They are also remarkable for containing more nitrogen than other vegetables, for which reason ammonia is generally evolved in their putrefaction. In medicine they are eminently stimulant and antiscorbutic. None are really poisonous, although very acrid. The root of Is at is tinct or i a affords a blue coloring matter. - The order is divided into 173 genera and 1,600 species. The greatest part of the species are found in the temperate zone. About 100 are peculiar to N. America.