Rosa arkansana var. arkansana

General:
Low shrub, 10 to 50 cm tall, from a rhizome or runner; stems spindly, erect to spreading, sparsely to densely bristly with straight prickles of various sizes; stems dying back annually to near the ground.

Leaves:
Alternate, deciduous, odd-pinnately compound, the axis usually hairy and sometimes glandular; leaflets usually 9 or 11, elliptic to egg-shaped, 1-4 cm long, coarsely saw-toothed, the teeth often callus-tipped, softly short-hairy to smooth; stipules smooth to hairy, entire or glandular-blunt-toothed near the tip.

Flowers:
Inflorescence of several stalked flowers in a small cluster atop the main shoot of the season, or at the end of a lateral branchlet; corollas pink, sometimes white, saucer-shaped, 4-7 cm across, the petals 5, 15-25 mm long; calyces 5-lobed, the lobes lanceolate, long-tapering and narrowing then flaring below the tip, 10-25 mm long, stalked-glandular on the back, persistent, spreading in fruit; ovaries superior but enclosed in the urn-shaped floral tube (hypanthium); stamens numerous.

Fruits:
Achenes, 15 to 30, stiffly long-hairy especially on one side, enclosed by the fleshy hypanthium, which ripens into a reddish-purple, globe- to pear-shaped hip 8-12 mm long.

Source:  The Illustrated Flora of British Columbia