Rosaceæ

Rosaceæ, a natural order of exogenous plants, containing many species of great usefulness, and many that are in the highest esteem for their beauty and fruit. It contains trees, shrubs, and herbaceous plants, natives chiefly of cold and temperate regions, and far more abundant in the northern than in the southern hemisphere. Within the tropics they are chiefly but not exclusively found in elevated situations. The leaves are alternate, have stipules, and are either simple or compound. The flowers are generally hermaphrodite, but sometimes unisexual; the inflorescence various. The calyx is 4 to 5 lobed, generally 5-lobed; the petals as many as the divisions of the calyx, or occasionally wanting, perigynous. The stamens are few or many, arising from the throat of the calyx; the ovary is sometimes solitary, sometimes there are several ovaries, each one-celled, with a lateral style, or a number of ovaries are united into a many-celled pistil; the ovules generally two or more. The fruit is sometimes a drupe; sometimes a pome; sometimes follicular; sometimes a nut; sometimes a collection of nuts enclosed in the fleshy tube of the calyx; sometimes a collection of small drupes forming a head, as in the raspberry; and sometimes, as in the straw- berry, it is an enlarged fleshy receptacle with the seeds imbedded on its surface. This natural order contains at least 1000 known species; but in some of the genera, as Rosa and Rubus, the determination of the species is attended with great difficulty, and varieties—sometimes reckoned species—are numerous. The order, as generally received, is divided into a number of sub-orders, several of which have by some botanists been elevated to the rank of distinct orders, as Amygdaleæ, Pomaceæ, Sanguisorbeæ. See also ROSE, RUBUS, STRAWBERRY, POTENTILLA, TORMENTIL, AGRIMONY, GEUM, SPIREA, CUSCO, &c.