Ros. Monogr., 21. 1820.
Shrubs, forming thickets or ± open stands. Stems erect, slender to stout, 2–20 (–50) dm, densely or openly branched; bark dark red, glabrous; infrastipular prickles usually paired, sometimes absent, erect or curved to hooked, declined, or introrse, usually subulate, sometimes terete or flattened, stout, (0.5–) 2–7 (–13) × 1–5 mm, base glabrous, internodal prickles usually sparse to dense, often intermixed with aciculi. Leaves 2.5–8 (–12) cm; stipules (6–) 9–16 (–25) × 2–5 mm, auricles usually flared, 2–6 mm, margins usually entire, sometimes undulate, sparsely serrate, eglandular or glandular, surfaces glabrous, eglandular, rarely glandular; petiole and rachis with pricklets sparse or absent, usually puberulent-velutinous hairs 0.1 (–0.5) mm, rarely glabrate, eglandular, rarely stipitate-glandular; leaflets 5–7 (–9), terminal: petiolule 3–12 mm, blade obovate, elliptic, or ovate, rarely cordate, (6–) 12–35 (–40) × 6–20 (–26) mm, usually widest at or above middle, membranous, base cuneate, rarely obtuse, margins 1 (–2+) -serrate, teeth (5–) 7–14 per side, on distal 1/2–4/5 of margin, acute, usually eglandular, apex acute or obtuse, abaxial surfaces pale green, glabrous, sometimes pubescent or puberulent, eglandular, sometimes glandular, adaxial green, rarely glaucous, dull, glabrous. Inflorescences usually panicles, sometimes corymbs or solitary flowers, 1–10 (–25+) -flowered. Pedicels erect, slender, 10–20 (–33) mm, glabrous, eglandular, rarely stipitate-glandular; bracts 2, ovate or lanceolate, (6–) 9–20 × 4–9 mm, margins entire or ciliate, eglandular, sometimes sparsely glandular, surfaces pubescent, eglandular. Flowers (2–) 3–3.5 (–5) cm diam.; hypanthium ovoid, rarely oblong or globose, 3–6 × 3–5 mm, glabrous, eglandular, rarely stipitate-glandular, neck (0–) 0.5–1 × 1.5–3.5 mm; sepals spreading, ovatelanceolate, 8–15 (–21) × 1.5–2.5 mm, tip 4–6 × 0.3–1 (–2) mm, margins usually entire, abaxial surfaces glabrous, eglandular, sometimes sessile or stipitate-glandular; petals single, pink to deep rose, 15–20 (–25) × 15–20 (–25) mm; stamens 65; carpels (16–) 20–40 (–50), styles exsert 1–2 mm beyond stylar orifice (2–2.5 mm diam.) of hypanthial disc (3–5 mm diam.). Hips red, orange-red, or purplish red, globose, depressed-globose, ovoid, oblong, or urceolate, 6–13 (–16) × 5–12 (–15) mm, fleshy, usually glabrous, eglandular, neck (0–) 1–2 × 3–4 (–7) mm; sepals persistent, erect to spreading. Achenes basiparietal, 15–40, tan to dark tan, (3.5–) 4–5 (–6) × 2–4 mm.
Alta., B.C., Man., N.W.T., Ont., Sask., Yukon, Alaska, Ariz., Calif., Colo., Idaho, Iowa, Kans., Minn., Mont., N.Dak., N.Mex., Nebr., Nev., Okla., Oreg., S.Dak., Tex., Utah, Wash., Wyo., n Mexico
Subspecies 6 (6 in the flora).
Rosa woodsii is the most common and most variable rose species in central and western North America (W. H. Lewis and B. Ertter 2007, 2010). Among its diagnostic features are relatively slender prickles, usually 1-serrate, eglandular leaflets, and a finely velutinous indument of 0.2–0.5 mm hairs on petioles and rachises. Its range extends from the prairies of Canada and the United States to inland Alaska and to north-central New Mexico, California east of the Cascade Mountains and Sierra Nevada, and northern Mexico.
At least 25 species names have been proposed to accommodate variation encompassed here within Rosa woodsii; some of these names have been used extensively (for example, R. fendleri Crépin, R. macounii Greene). The six subspecies recognized here represent significant morphological tendencies occurring in well-defined ecogeographic settings (W. H. Lewis and B. Ertter 2007, 2010). Localized varieties are recognized within two of the subspecies. Plants with intermediate characteristics often occur in transitional zones, and occasional anomalous collections display features not otherwise characteristic of a given ecogeographic region.
Leaves of Rosa woodsii inhibit HIV-1 replication in acutely infected cells. Both oleanolic and pomolic acids were identified as anti-HIV agents (Y. Kashiwada et al. 1998). Root decoctions of R. woodsii were drunk by the Shoshoni as a blood tonic for general debility and to treat diarrhea, and also by the Paiute for treating diarrhea (W. H. Lewis and M. P. F. Elvin-Lewis 2003).
|1||Infrastipular prickles usually erect (erect or curved in subsp. gratissima, rarely curved in subsp. woodsii), sometimes absent; sepals abaxially eglandular, rarely stipitate-glandular (except subsp. woodsii n of 49° parallel); mostly w of Wasatch Range or e of Continental Divide||> 2|
|1||Infrastipular prickles usually curved or hooked, rarely absent; sepals often abaxially stipitate-glandular (except subsp. puberulenta); centered in Colorado Plateau Subprovince||> 4|
|2||Shrubs 2–10(–20) dm; stems usually densely branched; terminal leaflets usually obovate; centered in prairies and plains e of Continental Divide, occasionally extending w through passes.||Rosa woodsii subsp. woodsii|
|2||Shrubs usually 10–30(–50) dm; stems openly to densely branched; terminal leaflets ovate, ovate-elliptic, obovate, or elliptic; mostly within or w of Wasatch Range and n Rocky Mountains||> 3|
|3||Prickles sparse or absent on distal stems and branches; stems openly branched; inflorescences (1–)3–10(–25)-flowered; centered in n Great Basin and Columbia Plateau.||Rosa woodsii subsp. ultramontana|
|3||Prickles usually abundant on distal stems and branches; stems densely branched; inflorescences 1–3(–5+)-flowered; centered in Mojave Desert.||Rosa woodsii subsp. gratissima|
|4||Shrubs 2–10(+) dm; stems usually densely branched; terminal leaflets obovate, sometimes ovate or elliptic; high montane forests to scrub oak woodlands, 2100–3300 m.||Rosa woodsii subsp. manca|
|4||Shrubs 10–25+ dm; stems openly branched; terminal leaflets elliptic, rarely cordate or ovate; riparian sites in bottomlands, extending into mountains along waterways, 1300–2400 m||> 5|
|5||Sepals usually eglandular abaxially; prickles usually falcate, sometimes erect, declined, or introrse; terminal leaflets 20–40 mm; center of Colorado Plateau Subprovince.||Rosa woodsii subsp. puberulenta|
|5||Sepals usually densely stipitate-glandular abaxially; prickles usually strongly curved or hooked, sometimes introrse; terminal leaflets 10–30 mm; Apachian and s edge of Colorado Plateau Subprovinces.||Rosa woodsii subsp. arizonica|
"dm" is not declared as a valid unit of measurement for this property.