ROSA GALLICA.—RED ROSE.—The petals of Rosa gallica (Fam. Rosaceae), a shrub indigenous to southern Europe and probably western Asia, and extensively cultivated in all parts of the world. The petals are obtained from cultivated plants before the expansion of the flower, the lower clawed portion usually being removed; they are used fresh or are carefully dried and preserved. The chief supply of the drug is from the southern portion of France.
Description.—Imbricated, numerous, usually in small cones; petals broadly ovate, the upper part rose-colored and retuse, the lower part brownish-red, more or less rounded, acute or truncate, with numerous papillae and fine longitudinal veins; texture velvety; odor agreeable; taste astringent and slightly bitter.
Inner Structure.—(Fig. 138). The upper epidermal cells modified to conical papillae and containing a purplish-red cell sap, a loose mesophyll composed of 2 to 10 rows of cells, in among which are the fibrovascular bundles with spiral tracheae, and a lower epidermis of rectangular cells filled with a purplish-red cell sap.
Constituents.—Volatile oil in a small amount; a yellow, crystalline glucoside quercitrin, which yields, on decomposition, quercetin; tannin and gallic acids. The coloring principle is soluble in water and alcohol and gives a deep yellowish-red color with acids; a green color changing to brown with alkalies; purple or violet with potassium alum or iodin solutions; and a deep blue with ferrous or ferric salts.
|Fig. 138. Rosa Gallica: A, surface view of the ventral or upper surface of petal, showing polygonal cells, the radiating line indicating the folds formed by the papillae. B, surface view of cells on the dorsal or lower surface of the petal with inner projections being sometimes of a T-shape. C, cross section from the middle of the petal, showing the upper epidermal cells with papillae (v), loose mesophyll cells (m), some of which contain small crystals of calcium oxalate (k) and starch grains (st); and cells of lower epidermis in which the papillae are wanting. D, transverse section through the base of a petal, the letters as in C. Fragments found in the powder show in addition to the cellular elements of the peatls, a glandular hair (E) and non-glandular hairs (F) which occur on the stems and sepals; and pollen grains (G).--Re-drawn from plates of Hans Kramer, in Ber. d. d. pharm. Ges., 1907, p. 354.|
Allied Plants.—The petals of Rosa centifolia are collected after the expansion of the flowers and dried; they are brownish and not so fragrant as those of Rosa gallica. The flowers of cultivated plants of Rosa damascena yield the commercial volatile oil of rose.
ROSAE CANINAE FRUCTUS.—ROSE HIPS.—The fresh fruits of Rosa canina and other allied species of Rosa (Fam. Rosaceae), a shrub common throughout Europe and the British Isles.
Description.—Ovoid, from 15 to 20 mm. in length, externally, of a red or scarlet color, smooth and shiny, and having at the summit the 5 calyx-teeth, beyond which project the hairy appendages of the achenes; pericarp of a fleshy texture, becoming on maturity, especially after frost, soft and pulpy, the pulp of the sarcocarp being of an orange color and an agreeable, acidulous taste; the hollow receptacle bears on its inner surface numerous small, hard achenes, which, as well as the walls of the former, are covered with unicellular, thick-walled hairs.
Powder.—Dark brownish-red; non-glandular hairs of torus unicellular, from 0.5 to 2 mm. in length, about 0.035 mm. in width, gradually tapering toward the base as well as the summit, having very thick walls and narrow lumina; parenchyma cells with brownish-red masses of plastids; calcium oxalate crystals in rosette aggregates from 0.035 to 0.050 mm. in diameter; sclerenchymatous cells and fibers of seed-coat with colorless, rather thick walls and numerous simple and branching pores; an inner epidermis of elongated cells containing a brown pigment; the cells of the embryo with small, nearly spheroidal aleurone grains and considerable oil.
Constituents.—Citric acid, 3 per cent.; malic acid, 8 per cent.; mucilage, 25 per cent.; an uncrystallizable sugar, 30 per cent.; also citrates, malates and mineral salts.