Rosa bridgesii

Crépin ex Rydberg

Bull. Torrey Bot. Club 44: 83. 1917.

Common names: Sierran ground rose
EndemicIllustrated
Synonyms: Rosa gymnocarpa var. pubescens S. Watson R. spithamea var. solitaria L. F. Henderson R. spithamea var. subinermis Engelmann
Treatment appears in FNA Volume 9. Treatment on page 118. Mentioned on page 97, 116, 117, 119.

Subshrubs, forming open colonies. 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. 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. Inflorescences corymbs, 1 or 2 (–7) -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. 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.). 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. Achenes basiparietal, 1–11, cream to pale-brown, 3.5–5 (–6.5) × 2.5–4 mm. 2n = 14, 28.


Phenology: Flowering May–Aug.
Habitat: Open forest floors, meadow edges, rocky outcrops, midmontane forests, shade to sun
Elevation: 700–2500 m

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.

Selected References

None.

Lower Taxa

None.

"dm" is not declared as a valid unit of measurement for this property.

... more about "Rosa bridgesii"
eglandular +, setose-glandular +, stipitate +  and sessile +
stipitate-glandular +  and puberulent +
0.5 cm5 mm <br />0.005 m <br /> (0.65 cm6.5 mm <br />0.0065 m <br />) +
cream +  and pale-brown +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
basiparietal +  and basal +
2.5mm +  and 4mm +
finely puberulent +  and glabrate +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
Walter H. Lewis +, Barbara Ertter +  and Anne Bruneau +
Crépin ex Rydberg +
gray +  and dark-brown +
glabrous +  and glaucous +
exfoliating +
compound +  and simple +
opposite +  and alternate +
internodal +
rounded-obtuse +
smaller +
3 cm30 mm <br />0.03 m <br /> (5 cm50 mm <br />0.05 m <br />) +
2.5 cm25 mm <br />0.025 m <br /> (3 cm30 mm <br />0.03 m <br />) +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +
lustrous +  and dull +
widely elliptic-cuneate +  and more or less orbiculate +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +
? (?) +  and ? (?) +
8mm +  and 25mm +
persistent +
0.3 cm3 mm <br />0.003 m <br /> (1 cm10 mm <br />0.01 m <br />) +
lanceolate +
0.1 cm1 mm <br />0.001 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
free +  and distinct +
Sierran ground rose +
1-16(-50)-flowered +
rarely puberulent +  and tomentose +
rarely puberulent +  and tomentose +
Calif. +  and Oreg. +
not +  and aggregated +
700–2500 m +
2.5 cm25 mm <br />0.025 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
not +  and aggregated +
eglandular +  and glandular +
urceolate +, pyriform +, oblong +, ellipsoid +, ovoid-obovoid +  and globose +
Open forest floors, meadow edges, rocky outcrops, midmontane forests, shade to sun +
stipitate-glandular +
0 cm0 mm <br />0 m <br /> (0.02 cm0.2 mm <br />2.0e-4 m <br />) +
0.8 cm8 mm <br />0.008 m <br /> (1 cm10 mm <br />0.01 m <br />) +
1.5 cm15 mm <br />0.015 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
1 cm10 mm <br />0.01 m <br /> (1.8 cm18 mm <br />0.018 m <br />) +
setose +  and glabrous +
ovoid +  and depressed-globose +
0.7 cm7 mm <br />0.007 m <br /> (1.4 cm14 mm <br />0.014 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
conic +  and flat +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
purplish black +, purplish red +, orange-red +  and red +
0.4 cm4 mm <br />0.004 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
setose +  and glabrous +
0.2 cm2 mm <br />0.002 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
leathery +  and fleshy +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
1-16(-50)-flowered +
crassinucellate +
3-foliate +  and compound +
11 cm110 mm <br />0.11 m <br /> (17 cm170 mm <br />0.17 m <br />) +
deciduous +
2.5 cm25 mm <br />0.025 m <br /> (11 cm110 mm <br />0.11 m <br />) +
leathery +  and membranous +
petiolulate +  and subsessile +
elliptic +  and obovate more or less oblong obovate-elliptic lanceolate-elliptic or obovate-oblong +
stipitate-glandular +
2+-crenate +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
distinct +
1 +, 0.5mm +  and 1mm +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
inferior +  and superior +
clustered +, biseriate +  and superposed +
1-30(-50)-flowered +
2 cm20 mm <br />0.02 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
stipitate-glandular +  and glabrous +
0.5 cm5 mm <br />0.005 m <br /> (1.7 cm17 mm <br />0.017 m <br />) +
free +  and distinct +
1 cm10 mm <br />0.01 m <br /> (2 cm20 mm <br />0.02 m <br />) +
1 cm10 mm <br />0.01 m <br /> (2 cm20 mm <br />0.02 m <br />) +
hairy +, fine +  and glabrous +
1.5 cm15 mm <br />0.015 m <br /> (2 cm20 mm <br />0.02 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (2 cm20 mm <br />0.02 m <br />) +
Flowering May–Aug. +
adnate +, free +, connate +  and distinct +
0.3 cm3 mm <br />0.003 m <br /> (1 cm10 mm <br />0.01 m <br />) +
subulate +  and flattened +
0.2 cm2 mm <br />0.002 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
Bull. Torrey Bot. Club +
hairy +, fine +  and glabrous +
0.5 cm5 mm <br />0.005 m <br /> (?) +
not arillate +
3 cm30 mm <br />0.03 m <br /> (4 cm40 mm <br />0.04 m <br />) +
persistent +
free +  and distinct +
erect +  and spreading +
lanceolate +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
rarely densely puberulent +  and tomentose +
Endemic +  and Illustrated +
free +  and distinct +
flexuous +
procumbent +  and sprawling +
1 +  and 20 +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
persistent +
not elongate +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
glabrous +  and stipitate-glandular +
Rosa gymnocarpa var. pubescens +, R. spithamea var. solitaria +  and R. spithamea var. subinermis +
Rosa bridgesii +
Rosa sect. Rosa +
species +
0mm +  and 4mm +
0.5 cm5 mm <br />0.005 m <br /> (?) +
gland-tipped +
8 +  and 12 +
inconspicuous +
enlarged +  and small +
small +  and miniature +