Rosa gymnocarpa Torr. & Gr.

A shrub usually 2 to 5 ft high in the wild, though said occasionally to attain 10 ft; stems slender, with straight, needle-like prickles often intermixed with bristles, sometimes almost unarmed. Leaflets five or seven, less commonly nine, 3⁄8 to 3⁄4 in. long, elliptic to ovate or roundish, usually obtuse at the apex, sometimes slightly glandular beneath, teeth usually compound, glandular or not. Flowers rosy pink, 1 to 11⁄2 in. across, solitary or two to four in a cluster. Pedicels glandular rosy pink, 1 to 11⁄2 in. across, solitary or two to four in a cluster. Pedicels glandular-bristly, up to 1 in. long. Sepals glabrous and usually eglandular, 1⁄4 to barely 1⁄2 in. long, triangular or ovate, with a slender prolongation. Fruits smooth, red, globose, pear-shaped or ellipsoid, to about 3⁄8 in. long; sepals, disk and styles deciduous from the ripe fruit.

Native of western North America; introduced about 1893. This pretty and graceful rose is the type of the mainly Asiatic section or subsection Gymnocarpae, characterised by the shedding of the entire top of the receptacle from the ripe fruit. It is closely allied to R. willmottiae and difficult to distinguish from R. fargesiana, a Chinese species not described here. Other species in this group are R. beggeriana and R. albertii.

This species is studied by G. A. Boulenger in Bull. Jard. Bot. Brux., Vol. 14 (1937), pp. 279–88.