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pygmy rose, Sierran dwarf rose, Sierran ground rose, wood rose

harsh downy-rose, whitewoolly rose

Habit Subshrubs, forming open colonies. Shrubs, climbing; rhizomatous or not.
Stems

erect, (1–)2–4(–8) dm, openly branched;

bark often glaucous when young, gray to dark brown with age, glabrous;

infrastipular prickles paired, erect, largest ± flattened, subulate, 3–10 × 2–7 mm, base glabrous, internodal rare or absent, smaller, mixed with aciculi, eglandular.

arching, 7–20(–30) dm, internodes long;

distal branches spreading, bark pale green;

infrastipular prickles single or paired, curved or ± erect, 3–6 × 2.5–3.5 mm, lengths ± uniform, internodal prickles sometimes mostly smaller, with aciculi, rarely absent.

Leaves

2.5–11 cm;

stipules 5–10 × 2–4 mm, auricles flared, 1–3 mm, margins entire, usually sessile-glandular, surfaces glabrous, stipitate-glandular;

petiole and rachis with sparse pricklets, glabrous or densely fine hairy hairs to 0.2 mm, densely stipitate-glandular;

leaflets (3–)5–7, terminal: petiolule 3–20 mm, blade obovate or widely elliptic-cuneate to ± orbiculate, 10–30(–50) × 8–25(–30) mm, membranous to ± leathery, base rounded-obtuse, margins 2+-crenate, teeth 8–12 per side, obtuse, gland-tipped, apex obtuse to truncate, abaxial surfaces gray-green, finely puberulent, sometimes sparsely stipitate-glandular, adaxial green, dull, finely puberulent to glabrate.

deciduous, 5–7.5(–11) cm;

stipules 10–16(–20) × 3–4 mm, auricles 2–5 mm, margins densely glandular-ciliate, surfaces tomentose, often glandular abaxially;

petiole and rachis with sparse pricklets, tomentulose, glandular;

leaflets 5–7, terminal: petiolule 6–8 mm, blade orbiculate to ovate-lanceolate or elliptic, 15–30(–60) × 8–22(–50) mm, base obtuse, margins 1- or multi-serrate, teeth 13–20 per side, apex acute, abaxial surfaces tomentose, usually resinous-glandular, glands resin-scented, adaxial pale or grayish green, dull, glabrous or pubescent.

Inflorescences

corymbs, 1 or 2(–7)-flowered.

panicles, 1–6-flowered.

Pedicels

erect, relatively slender, 5–17 mm, glabrous, eglandular or stipitate-glandular;

bracts 1–3, lanceolate, 3–10 × 1–6 mm, margins entire, stipitate-glandular, surfaces glabrous, eglandular.

erect, (11–)20–35 mm, densely stipitate-glandular;

bracts 2, ovate-lanceolate, 13–14 × 5–7 mm, margins ciliate-glandular, surfaces tomentose, glandular or eglandular.

Flowers

2.5–3.5 cm diam.;

hypanthium ovoid-globose to widely urceolate, 4–5 × 3–4 mm, glabrous, rarely sparsely setose, usually eglandular, neck 0.5–1(–2) × 1.5–3 mm;

sepals spreading, lanceolate, 6–14 × 2–3 mm, tip 0–4 × 0.5 mm, margins entire, abaxial surfaces puberulent, usually stipitate-glandular;

petals single, deep pink, 10–20 × 10–20 mm;

carpels 10–30, styles exsert 0.5–1 mm beyond stylar orifice (1–1.5 mm diam.) of hypanthial disc (2–4 mm diam.).

3.5–5 cm diam.;

hypanthium ovoid, 6–7 × 4 mm, stipitate-glandular, setose, rarely eglandular, neck 1.5 × 2 mm;

sepals spreading or erect, ovate-lanceolate, 15–25 × 2–3 mm, margins pinnatifid, tip 4–5 × 1–1.5 mm, abaxially densely stipitate-glandular;

petals pink, rarely white, 8–15 × 10–15 mm;

carpels 26–34, styles glabrous or villous, exsert 2–2.5 mm beyond stylar orifice (1 mm diam.) of hypanthial disc (2–4 mm diam.).

Hips

scarlet, ovoid to depressed-globose to pyriform, (8–)10–18 × 7–14 mm, fleshy, glabrous, rarely sparsely setose distally, eglandular, neck 1 × 2.5–4.5 mm;

sepals persistent, erect.

dark red, oblong, ovoid, or globose, 10–15 × 10–12 mm, glabrous, stipitate-glandular at least proximally, neck 1 × 5–6 mm;

sepals deciduous after anthesis, spreading or reflexed.

Achenes

basiparietal, 1–11, cream to pale brown, 3.5–5(–6.5) × 2.5–4 mm.

ca. 23, tan, 4–4.5 × 2 mm.

2n

= 14, 28.

= 35.

Rosa bridgesii

Rosa tomentosa

Phenology Flowering May–Aug. Flowering Jun–Jul.
Habitat Open forest floors, meadow edges, rocky outcrops, midmontane forests, shade to sun Roadside thickets, hedgerows, woodland edges
Elevation 700–2500 m (2300–8200 ft) 0–300 m (0–1000 ft)
Distribution
from FNA
CA; OR
[WildflowerSearch map]
[BONAP county map]
from FNA
NC; NY; TN; TX; VT; PE; Europe [Introduced in North America]
[BONAP county map]
Discussion

As here circumscribed, Rosa bridgesii is the Sierran-Cascade counterpart of R. spithamea, encompassing previous references to R. pinetorum and R. spithamea from the Sierra Nevada and most applications of R. yainacensis. The species is the low-growing, openly rhizomatous rose of midmontane forests in the Sierra Nevada and southern Cascade Range of California and Oregon. Finely puberulent leaflets help distinguish non-fruiting R. bridgesii from sympatric R. gymnocarpa, which has glabrous leaflets. Plants from Oregon differ from Sierran plants in that prickles are less likely to be infrastipular only.

In the phylogenetic analysis by A. Bruneau et al. (2007), Rosa bridgesii and R. spithamea comprise a distinct clade more closely related to Asian species than to others from western North America.

Rosa bridgesii has been conserved against R. calvaria Greene, R. covillei Greene, R. crenulata Greene, R. myriadenia Greene, and R. yainacensis Greene (B. Ertter 2007b). Only R. calvaria and R. crenulata are unambiguous synonyms of R. bridgesii; the taxonomic identity of the other names remains unresolved and may involve hybridization with other species.

On the basis of pollen size, E. W. Erlanson (1931) believed that material falling within the current circumscription of Rosa bridgesii was tetraploid (2n = 28). In a subsequent paper (1934), she reported a diploid somatic count (2n = 14) for R. calvaria, a synonym of R. bridgesii. Recent flow cytometry indicates a tetraploid condition for the sampled specimen of R. bridgesii (A. Bruneau et al., unpubl. data). It is possible that both ploidy levels are present within the species.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

A rare introduction from Europe, Rosa tomentosa was reported by P. A. Rydberg (1918) from North Carolina and Texas and collected by Fernald (GH) in Queens County, Prince Edward Island. The species is also reported to occur in disturbed areas in New York, Tennessee, and Vermont (USDA PLANTS database). Whether the species has persisted at any of these occurrences is unknown; it is not currently included in the flora of Canada (H. G. Scoggan 1978–1979; VASCAN).

Rosa tomentosa is best recognized by its climbing habit, leaflets that are abaxially, and sometimes adaxially, tomentose or pubescent, and relatively long petioles. Sepals are spreading or reflexed after anthesis and deciduous when hips mature. Prickles are usually erect, and the stylar orifices are small (1 mm diam.).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 9, p. 118. FNA vol. 9, p. 92.
Parent taxa Rosaceae > subfam. Rosoideae > tribe Roseae > Rosa > subg. Rosa > sect. Rosa Rosaceae > subfam. Rosoideae > tribe Roseae > Rosa > subg. Rosa > sect. Caninae
Sibling taxa
R. acicularis, R. arkansana, R. blanda, R. bracteata, R. californica, R. canina, R. carolina, R. cinnamomea, R. foliolosa, R. gallica, R. glauca, R. gymnocarpa, R. laevigata, R. lucieae, R. minutifolia, R. mollis, R. multiflora, R. nitida, R. nutkana, R. palustris, R. pinetorum, R. pisocarpa, R. rubiginosa, R. rugosa, R. setigera, R. sherardii, R. spinosissima, R. spithamea, R. stellata, R. tomentosa, R. virginiana, R. woodsii
R. acicularis, R. arkansana, R. blanda, R. bracteata, R. bridgesii, R. californica, R. canina, R. carolina, R. cinnamomea, R. foliolosa, R. gallica, R. glauca, R. gymnocarpa, R. laevigata, R. lucieae, R. minutifolia, R. mollis, R. multiflora, R. nitida, R. nutkana, R. palustris, R. pinetorum, R. pisocarpa, R. rubiginosa, R. rugosa, R. setigera, R. sherardii, R. spinosissima, R. spithamea, R. stellata, R. virginiana, R. woodsii
Synonyms R. gymnocarpa var. pubescens, R. spithamea var. solitaria, R. spithamea var. subinermis
Name authority Crépin ex Rydberg: Bull. Torrey Bot. Club 44: 83. (1917) Smith: Fl. Brit. 2: 539. (1800)
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