Characters.—Trunk usually cylindrical, when a terminal bud only is developed, becoming conical and branched when several develope: consisting of cellular tissue, among which the vascular tissue is mixed in bundles, usually without any distinction of bark, wood, and pith, and destitute of medullary rays; increasing in diameter by the addition of new matter to the centre. Leaves frequently sheathing at the base, and not readily separating from the stem by an articulation, mostly alternate, generally parallel-veined, rarely netted. Flowers usually having a ternary division; the calyx and corolla either distinct or undistinguishable in colour and size, or absent. Embryo with but one cotyledon; if with two, then the accessory one is imperfect, and alternate with the other; radicle usually enclosed within the substance of this embryo, through which it bursts when germinating (Lindley, chiefly).
The Elements of Materia Medica and Therapeutics, Vol. II, 3th American ed., was written by Jonathan Pereira in 1853.