Cruciferae
A large and important order of annual, biennial, or perennial herbs, rarely suffruticose. Flowers racemed; sepals four, the two lateral ones often larger and saccate at the base, imbricate in bud; petals four, placed crosswise, imbricate in bud; stamens six (rarely one, two, or four), hypogynous, the two outer opposite the lateral sepals, the four inner longer, in pairs opposite the other sepals. Fruit a long or short two-celled and two-valved capsule (rarely indehiscent). Leaves radical or alternate, exstipulate. The order, sometimes called Brassicaceae, comprises about 170 genera and about 1200 species; they are distributed over all temperate and cold regions, but chiefly belong to the Old World. All are nitrogenous (and contain sulphur), pungent, stimulant, anti-scorbutic, often acrid. Many of them are highly-esteemed plants, such as the Broccoli, Cabbage, Cress, Turnip, &c. The following are some of the best-known genera: Arabis, Brassica, Cheiranthus, and Hesperis.