Characters.—Flowers unisexual: males amentaceous; females aggregate or amentaceous. Males: Stamens 5 to 20, inserted into the base of the scales, or of a membranous valvate calyx, generally distinct. Females: Ovaries crowned by the rudiments of an adherent (superior) calyx, seated within a coriaceous involucre (cupule) of various figure, and with several cells and several ovules, the greater part of which are abortive; ovules twin or solitary, pendulous or peltate: stigmas several, subsessile, distinct. Fruit a bony or coriaceous, 1-celled nut, more or less inclosed in the involucre. Seeds solitary, 1, 2, or 3: embryo large, with planoconvex, fleshy cotyledons, and a minute superior radicle.—Trees or shrubs. Leaves with stipules, alternate, simple, often with veins proceeding straight from the midrib to the margin (Lindley).
Properties.—The prevailing quality of this order is astringency, owing to the presence of tannic acid.
Besides the species presently to be described, the following may be here briefly referred to: Quercus tinctoria, or the Black Oak, is a native of America. Its bark, called quercitron, is used by dyers. In ihe United States it is employed medicinally, but it is said to be disposed to irritate the bowels.—The large capsules or acorn cups of Quercus Aegilops are imported from the Levant, under the name of Velonia. They are astringent, and are employed by dyers.—A saccharine substance exudes from the leaves of Quercus mannifera in Kurdistan. [Lindley, Botanical Register, May and June, 1810.]