Rosa blanda

Aiton

Hort. Kew. 2: 202. 1789.

Common names: Meadow or smooth rose rosier inerme
EndemicIllustrated
Synonyms: Rosa johannensis Fernald R. rousseauiorum B. Boivin R. subblanda Rydberg R. williamsii Fernald
Treatment appears in FNA Volume 9. Treatment on page 105. Mentioned on page 77, 95, 100, 104.

Shrubs, forming thickets. Stems erect or arching, (5–) 10–20 dm, sparsely branched; bark green when young, red to orange-red with age, proximally glaucous, glabrous; infrastipular prickles absent, internodal prickles rare, sparse, distal aciculi rare. Leaves 8.5–11 cm; stipules (9–) 15–25 × 4–6 mm, auricles usually flared, (2.5–) 4–6 mm, margins entire or serrate, sparsely to densely stipitate-glandular, surfaces glabrous, sometimes pubescent, eglandular or glandular; petiole and rachis with pricklets rare or absent, glabrous or puberulent to pubescent, sessile or stipitate-glandular, sometimes eglandular; leaflets 5–7 (–9), terminal: petiolule 5–9 (–13) mm, blade elliptic or ovate, sometimes obovate, (15–) 25–40 (–55) × (8–) 12–20 (–30) mm, membranous, margins 1-serrate, teeth 10–26 per side, acute, sometimes black gland-tipped, apex acute, sometimes obtuse, abaxial surfaces pale green, glabrous, sometimes pubescent or tomentulose, eglandular, adaxial green, dull to ± lustrous, glabrous, sometimes marginally hairy. Inflorescences corymbs, 1–5 (–10) -flowered. Pedicels erect, slender, 14–25 mm, glabrous, eglandular, rarely sparsely stipitate-glandular; bracts 1 or 2, ovatelanceolate, 14–20 × 2–8 mm, margins entire, sometimes undulate, irregularly serrate, short-stipitate-glandular, surfaces glabrous, glandular. Flowers 3–6 (–7) cm diam.; hypanthium ovoid or globose, 4–5 × 4.5–5 mm, glabrous, eglandular, rarely stipitate-glandular, neck (0–) 0.5–0.8 × 3–3.5 mm; sepals usually erect usually forming a beak-cap or ± reflexed, ovatelanceolate, (12–) 20–30 × 2.5–3.5 mm, tip 2.5–4 × 0.5–1.5 mm, margins entire or pinnatifid, abaxial surfaces glabrous, stipitate-glandular, rarely eglandular; petals single, pink or rose, 13–26 × 12–26 mm; stamens 115; carpels 32–55, styles exsert 1–2 mm beyond stylar orifice (1.5 mm diam.) of hypanthial disc (4 mm diam.). Hips red, subglobose to globose, sometimes ellipsoid, urceolate, or pyriform, 8–11 × 8–11 mm, fleshy, glabrous, eglandular, rarely sparsely stipitate-glandular, neck (0–) 0.5–1 (–1.5) × 3.5–4.5 mm; sepals persistent, erect or reflexed. Achenes basiparietal, 26, tan, 3.5–4 × 1.5–3 mm. 2n = 14.


Phenology: Flowering Jun–Jul.
Habitat: Thickets, grassy verges, edges of woods, ditches, stream banks, gravelly and sandy flats
Elevation: 0–700 m

Distribution

V9 153-distribution-map.jpg

Man., N.B., N.W.T., N.S., Ont., Que., Sask., Ill., Ind., Iowa, Maine, Mass., Mich., Minn., Mo., Nebr., N.H., N.Y., N.Dak., Ohio, Pa., R.I., S.Dak., Vt., W.Va., Wis., in c Europe

Discussion

Rosa blanda is best recognized by its erect, slender distal stems and branches without armature or, rarely, with internodal prickles and/or aciculi. In addition, auricles are flared, 4–6 mm; abaxial surfaces of sepals are stipitate-glandular, usually forming an erect beak-cap, and an average stamen number of 115, nearly double that of R. woodsii with 65.

M. Mercure and A. Bruneau (2008) described and genetically confirmed spontaneous hybrids between Rosa blanda and R. rugosa forming colonies along the St. Lawrence Estuary, Quebec. Analyses indicated that most of the hybrids were first generation; second generation and backcrosses were also detected. This is a recently established hybrid zone with the potential for introgression of the aggressive R. rugosa into native R. blanda and thereby a serious threat to the integrity of the native species.

A. Bruneau et al. (2007) found that, within Rosa blanda, previously recognized segregate species (R. johannensis, R. rousseauiorum, R. subblanda, R. williamsii) should not be considered specifically distinct from R. blanda, although populations representing R. williamsii might be worthy of subspecific recognition.

Selected References

None.

Lower Taxa

None.

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

... more about "Rosa blanda"
stipitate-glandular +, glabrous +, tomentulose +  and pubescent +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
basiparietal +  and basal +
1.5mm +  and 3mm +
hairy +  and glabrous +
dull +  and more or less lustrous +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
Walter H. Lewis +, Barbara Ertter +  and Anne Bruneau +
red +  and orange-red +
glabrous +  and glaucous +
exfoliating +
compound +  and simple +
opposite +  and alternate +
not cuneate +
4 cm40 mm <br />0.04 m <br /> (5.5 cm55 mm <br />0.055 m <br />) +
2 cm20 mm <br />0.02 m <br /> (3 cm30 mm <br />0.03 m <br />) +
2.5 cm25 mm <br />0.025 m <br /> (4 cm40 mm <br />0.04 m <br />) +
lustrous +  and dull +
obovate +, ovate +  and elliptic +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +
12mm +  and 20mm +
persistent +
1.4 cm14 mm <br />0.014 m <br /> (2 cm20 mm <br />0.02 m <br />) +
ovatelanceolate +
0.2 cm2 mm <br />0.002 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
free +  and distinct +
Meadow or smooth rose +  and rosier inerme +
1-16(-50)-flowered +
rarely puberulent +  and tomentose +
rarely puberulent +  and tomentose +
Man. +, N.B. +, N.W.T. +, N.S. +, Ont. +, Que. +, Sask. +, Ill. +, Ind. +, Iowa +, Maine +, Mass. +, Mich. +, Minn. +, Mo. +, Nebr. +, N.H. +, N.Y. +, N.Dak. +, Ohio +, Pa. +, R.I. +, S.Dak. +, Vt. +, W.Va. +, Wis. +  and in c Europe +
not +  and aggregated +
0–700 m +
3 cm30 mm <br />0.03 m <br /> (6 cm60 mm <br />0.06 m <br />) +
not +  and aggregated +
eglandular +  and glandular +
urceolate +, pyriform +, oblong +, ellipsoid +, ovoid-obovoid +  and globose +
Thickets, grassy verges, edges of woods, ditches, stream banks, gravelly and sandy flats +
1.8 cm18 mm <br />0.018 m <br /> (2.4 cm24 mm <br />0.024 m <br />) +
1.5 cm15 mm <br />0.015 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
0.8 cm8 mm <br />0.008 m <br /> (1.1 cm11 mm <br />0.011 m <br />) +
stipitate-glandular +  and glabrous +
pyriform +, urceolate +, ellipsoid +, subglobose +  and globose +
0.8 cm8 mm <br />0.008 m <br /> (1.1 cm11 mm <br />0.011 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 />) +
stipitate-glandular +  and glabrous +
0.2 cm2 mm <br />0.002 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
leathery +  and fleshy +
0.45 cm4.5 mm <br />0.0045 m <br /> (0.5 cm5 mm <br />0.005 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 +
8.5 cm85 mm <br />0.085 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 +
serrate +, entire +  and 1-serrate +
short-stipitate-glandular +  and stipitate-glandular +
pinnatifid +, entire +  and undulate +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
distinct +
0.5mm +  and 1mm +
0.35 cm3.5 mm <br />0.0035 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 +
1.4 cm14 mm <br />0.014 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
Rose (?) +  and Pink (?) +
free +  and distinct +
1.3 cm13 mm <br />0.013 m <br /> (2.6 cm26 mm <br />0.026 m <br />) +
1.2 cm12 mm <br />0.012 m <br /> (2.6 cm26 mm <br />0.026 m <br />) +
eglandular +  and sessile +
stipitate-glandular +, puberulent +  and pubescent +
0.9 cm9 mm <br />0.009 m <br /> (1.3 cm13 mm <br />0.013 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
Flowering Jun–Jul. +
adnate +, free +, connate +  and distinct +
mixed +  and paired +
declined +  and erect +
subulate +, deltate +, terete +  and hooked +
eglandular +  and sessile +
stipitate-glandular +, puberulent +  and pubescent +
0.5 cm5 mm <br />0.005 m <br /> (?) +
not arillate +
1.2 cm12 mm <br />0.012 m <br /> (2 cm20 mm <br />0.02 m <br />) +
persistent +
free +  and distinct +
reflexed +  and erect +
ovatelanceolate +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
rarely densely puberulent +  and tomentose +
Endemic +  and Illustrated +
free +  and distinct +
flexuous +
procumbent +  and sprawling +
arching +  and erect +
1 +  and 20 +
0.9 cm9 mm <br />0.009 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
1.5 cm15 mm <br />0.015 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (0.6 cm6 mm <br />0.006 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 +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
glandular +  and eglandular +
glabrous +  and pubescent +
Rosa johannensis +, R. rousseauiorum +, R. subblanda +  and R. williamsii +
Rosa blanda +
Rosa sect. Rosa +
species +
2.5mm +  and 4mm +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
black gland-tipped +
10 +  and 26 +
inconspicuous +
enlarged +  and small +
rhizomatous +  and open +
small +  and miniature +