Rocky Mountain rose

Rosa melina Greene, Pittonia 4: 10. 1899; R. oreophila Rydberg; R. pandorana Greene; R. underwoodii Rydberg

Shrubs, openly branched. Stems 4–10(–15) dm, internodes 2–2.5 cm; prickles (distal stems and fertile branches) infrastipular, curved or hooked, often stout, internodal sometimes present, smaller, rarely erect, sometimes absent. Terminal leaflet margins usually 2+-serrate, teeth gland-tipped, abaxial surfaces glandular or eglandular. Inflorescences usually 1(–5)-flowered. Sepals: abaxial surfaces sessile- or stipitate-glandular.

Flowering late Jun–Jul. Aspen, fir, spruce, and pine forest edges and clearings, stream edges and banks, brushy hillsides, peaks, ridges, grassy rocky slopes, meadows, canyon slopes; 2500–3800 m; Ariz., Colo., Idaho, N.Mex., Utah, Wyo.

Subspecies melina [6x (DNA)] is endemic to high elevations of the Rocky Mountains Biogeographic Province, where it is often associated with Populus tremuloides Michaux. Curved prickles, glandular sepals, and 2- or 3-serrate leaflets help distinguish subsp. melina where it overlaps with subsp. macdougalii in southeastern Idaho and northern Utah. Significant distributional overlap occurs also with Rosa woodsii subsp. manca, which can occur in mixed or adjacent populations. Subspecies melina is generally at higher elevations, flowers somewhat earlier than subsp. manca, and is hexaploid (the latter is diploid).