Order XII
CRUCIFERÆ. 1506 Sarcocápnos Dec. 1507 Fumária P. S.
The importance of this order to mankind, and the singular nature of its botanical characters, render it expedient to speak very fully upon it: in which the remarks of the learned M. Decandolle, who has paid Cruciferæ particular attention, will be chiefly followed. The order consists wholly of annual or perennial, often biennial herbs, occasionally assuming a suffrutescent habit; then, however, never exceeding the height of three feet. The roots are either thick and perennial, or annual or biennial and slender, almost always perpendicular and undivided. The young roots are tipped with a little sheath, called the coleorhiza, which is produced by the extended ruptured coat of the epidermis when the rootlet first appears. This is a curious character, and deserves attention. The stems are round or somewhat angular, branched, and often, even in the annual species, indurated at the base. The branches proceed from the axillæ of the leaves, but the uppermost ones are abortive in most cases. The racemes are always opposite to the leaves; sometimes the terminal branch is abortive when the raceme appears to be terminal; but this is merely owing to that circumstance. The leaves are simple, generally radical or alternate, rarely opposite. The flowers are either white, yellow, or purple, or in a few Cape species bright blue. The fruit is called either a siliqua or silicula, the former being a linear pod containing many seeds, the latter a roundish pod containing one or very few seeds, whence this order, which is the same as the Linnæan class Tetradynamia, is divided by Linnæus into two parts, called