General: Medium to tall shrub 0.5-3 m tall, spreading by rhizomes and often thicket-forming; stems stout to spindly, erect to arching, with a pair of large prickles (thorns) at each node, usually lacking internodal prickles; mature stems blackish.
Leaves: Alternate, deciduous, odd-pinnately compound, the leaf-stalk and axis glandular-hairy or short-hairy; leaflets 5 or 7 (9), elliptic to egg-shaped, 1-7 cm long, coarsely single- or double-toothed, somewhat glandular-short-hairy beneath; stipules usually glandular-blunt-toothed.
Flowers: Inflorescence of usually single, sometimes 2 or 3, stalked flowers on lateral branchlets; corollas pink, saucer-shaped, large (4-8 cm across), the petals 5, (2) 2.5-4 cm long; calyces smooth or glandular-bristly, 5-lobed, the lobes lanceolate, 1.5-4 cm long, long-tapering and narrowing then flaring below the tip, persistent; ovaries superior but enclosed in the urn-shaped floral tube (hypanthium); stamens numerous.
Fruits: Achenes, numerous, stiffly long-hairy on one side, enclosed by the fleshy hypanthium, which ripens into a purplish-red, globe- to pear-shaped hip 1-2 cm long.
Notes: Two varieties occur in BC:
1. Leaflets doubly saw-toothed, the teeth gland-tipped; infrastipular prickles becoming much enlarged and flattened toward base; plants mostly from west of Coast-Cascade Mountains................. var. nutkana
1. Leaflets singly saw-toothed, the teeth not gland-tiped; prickles rarely enlarged and flattened; plants mostly from east of Coast-Cascade Mountains..................var. hispida Fern.
1. Stipules deeply fringed or comb-like; inflorescence multiflowered..........R. multiflora
1. Stipules entire to coarsely toothed; inflorescence single to several-flowered.
1a. Prickles strongly curved, stout; calyx-lobes often with conspicuous lateral segments and usually reflexed after flowering.
2. Lower surface of leaflets stalked-glandular..............R. eglanteria
2. Lower surface of leaves not stalked-glandular (sometimes a few glands along leaf axis or midrib of leaflets)..................R. canina
1a. Prickles not or slightly curved, often slender; calyx-lobes usually without lateral segments, usually ascending or erect after flowering.
3. Calyx-lobes deciduous in fruit, 12 mm long or less; petals 15 mm long or less...............R. gymnocarpa
3. Calyx-lobes persistent in fruit, greater than 12 mm long; petals greater than 15 mm long.
4. Stems with well-defined infrastipular prickles (pair of prickles at or just below each node) or nearly unarmed.
5. Calyx-lobes usually glandular-bristly; leaflets finely toothed; plants from west of the Coast-Cascade Mountains............R. pisocarpa
5. Calyx-lobes usually not glandular-bristly; leaflets coarsely toothed.
6. Flowers small and clustered; calyx-lobes mostly 1-2 cm long and 2-3.5 mm wide at base; petals 1.2-2.5 cm long................R. woodsii
6. Flowers large and usually solitary; calyx-lobes mostly 1.5-4 cm long and 3-6 mm wide at base; petals 2.5-4 cm long.....................R. nutkana
4. Stems more or less bristly with slender prickles; infrastipular prickles, if any, like the others.
7. Flowers mostly solitary, usually on lateral branchlets of current season; leaflets usually 5 to 7 (9); petals more than 2 cm long..................R. acicularis
7. Flowers commonly clustered at ends of main shoots of current season as well as on lateral branchlets; leaflets (7) 9-11; petals less than 2.5 cm long..............R. arkansana
Source: Illustrated Flora of British Columbia (Vol. 4). (1999)
Habitat / Range
Mesic to moist thickets, forest edges, river terraces, shorelines, streambanks, clearings and roadsides in the lowland and montane zones; common throughout BC south of 55oN except in the Chilcotin area, infrequent northward, absent in NE BC; N to AK and S to CA, CO and UT.
Aboriginal people in the Pacific Northwest traditionally used this species as a food, medicine, and source of cultural material. The methanolic extract of the fruits of R. nutkana has been found to have inhibitory activity against methicillin-resistant Staphylococcus aureus (MRSA).
Reference:
Jovel, Eduardo M., Xi Ling Zhou, Dong Sheng Ming, Tanya R. Wahbe, and G.H. Neil Towers. 2007. Bioactivity-guided isolation of the active compounds from Rosa nutkana and quantitative analysis of ascorbic acid by HPLC Canadian Journal of Physiology and Pharmacology 85(9): 865–871.
Ecology
Ecological Framework for Rosa nutkana
The table below shows the species-specific information calculated from original data (BEC database) provided by the BC Ministry of Forests and Range. (Updated August, 2013)
A shade-tolerant/intolerant, submontane to montane, Western North American deciduous shrub distributed more in the Pacific than the Cordilleran region. Occurs on fresh to very moist, nitrogenrich soils within boreal, cool temperate, and cool mesothermal climates. Most frequent on floodplains; sporadic in nonforested communities and open-canopy forests on watershedding sites with fluctuating groundwater tables. Occasional on sites affected by ocean spray and brackish water. A nitrophytic species characteristic of Moder and Mull humus forms.
