A flowering shrub, prickly rose occurs throughout the forest understory of Denali and into the subalpine areas of the park, recognizable by its prickles, pink flowers and rose hips in fall. Shrubs grow 0.3-1.5 m tall from deep roots, by which the plant spreads itself vegetatively. Stems are red-brown and woody, covered in short gray prickles. The leaves are pinnately divided into five or seven sections; each leaflet elliptic with serrated margins. Leaves are slightly hairy on the underside. Flowers have five long, narrowly triangular sepals, green, with hairs, and five deep pink petals, rounded-ovate. The fruits are dark red rosehips, which develop beneath the persistent sepals. Rosa acicularis is a very distinctive species for Denali, as it is the only member of the genus Rosa occurring in the park.
Plants flower in June and July (Viereck and Little 2007). Fruits often persist through the winter. The species is a long-lived perennial (Crane 1990).
Plants are monoecious with bisexual flowers. The flowers are fragrant and insect-pollinated. Fruits are fleshy hips with 5-10 large seeds. In the wild, seeds are often dispersed by birds in the winter, and lay dormant through the following summer and winter (Densmore and Zasada 1977). According to Holloway (1996), germination can be induced by two months of warm stratification followed by three months of cold stratification. Plants also grow by rhizomes, producing large stands (Schori 2003). They can re-sprout from the roots after fire (Crane 1990b).
Small cynipid wasps of the genus Diplolepis produce leaf and stem galls on R. acicularis. Various rust fungi of the genus Phragmidium form orange rusty spots on R. acicularis (Arthur 1934).
Roses have been appreciated worldwide, for their smell, appearance, fruits, and not least of all, their medicinal properties. Rose petals and hips are edible, and an excellent source of vitamin C. Petals are occasionally eaten raw or turned into jelly, hips are collected and eaten raw, or made into preserves, candy or tea. The Dena'ina prepared a tea from the bark and used in treating colds, flu, fever, eye problems, stomach troubles, and menstrual problems (Garibaldi 1999). Stems and leaves are eaten by hares and other wildlife, the fruits eaten by birds and small mammals.
Prickly rose is a circumboreal species that ranges from Alaska across boreal Canada, south down the Rocky Mountains to New Mexico and eastwards along the northern tier to the Great Lakes and New England. Rosa acicularis occurs throughout Alaska from the Brooks Range south, although not reaching the Alaska Peninsula, and coastal areas in Prince William Sound, and much of southeast Alaska, where it is replaced by the closely related Rosa nutkana. The species is widespread and abundant in central Alaska. Abundant in the low elevations of the northern half of Denali, prickly rose also occurs in the northern subalpine and valleys on the south side of the park, particularly along the Yentna River.
Prickly rose is common on all slopes. Though is usually found on low inclines (average site: 8 degrees incline), its peak frequency and cover is at 12-20 degrees of slope. It has a moderately strong preference for south-facing aspects. Prickly rose has a wide elevational range in Denali, growing from 83 to 1203 meters; however, this is really a low elevational species, where its highest cover and frequency is at 300-500 meters, with < 300 meters a close second.