18. Rosa sikangensis T. T. Yu & T. C. Ku, Acta Phytotax. Sin. 18: 501. 1980.
川西蔷薇 chuan xi qiang wei
Shrubs small, 1–1.5 m tall. Branchlets terete, subglabrous; prickles in pairs below leaves, or sparse and intermixed with dense slender bristles; bristles glandular apically when young. Leaves including petiole 3–5 cm; stipules broad, mostly adnate to petiole, free parts ovate or hooked, pubescent or glabrous, margin glandular; rachis and petiole pubescent and glandular-pubescent; leaflets 7–9(–13), oblong or obovate, 6–10 × 4–8 mm, abaxially pubescent and glandular, adaxially glabrous or pubescent, base subrounded or broadly cuneate, margin densely doubly serrate, apex rounded-obtuse or truncate. Flower solitary, axillary, ca. 2.5 cm in diam.; pedicel 8–12 mm, glandular-pubescent; bracts absent. Hypanthium ovoid, glabrous. Sepals 4, ovate-lanceolate, abaxially sparsely pubescent and glandular, adaxially densely pubescent, margin entire, apex long acuminate. Petals 4, white, obovate, base broadly cuneate, apex emarginate. Styles free, much shorter than stamens, villous. Hip red, subglobose, ca. 1 cm in diam., abaxially glandular-pubescent; pedicel 8–12 mm, slender, glandular-pubescent. Fl. May–Jun, fr. Jul–Sep.
Scrub, river sides, roadsides; 2900--4200 m. Sichuan, Xizang, Yunnan.
One of us (Robertson) has seen no specimens of this species.
Two forms may be recognized: f. sikangensis, which has leaflets adaxially glandular and f. pilosa T. C. Ku (Bull. Bot. Res., Harbin 10(1): 1. 1990), which has leaflets adaxially eglandular or glandular only along the veins.