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cluster rose, cluster wild rose, peafruit rose, swamp rose

Photo is of parent taxon

cluster or pea rose, cluster rose, cluster wild rose, pea-fruit rose

Habit Shrubs, loosely clustered or in dense thickets. Plants often forming thickets.
Stems

ascending to erect, (2–)4–20(–25) dm, openly branched;

bark ± glaucous when young, dark reddish brown or dull red with age outer layer may exfoliate as thin ash gray peel, glabrous;

infrastipular prickles usually paired, erect, rarely curved, usually subulate, 2–10 × 2–4 mm, base glabrous, internodal prickles rare or absent.

loosely to densely clustered, 10–25 dm;

infrastipular prickles primarily (1–)2, 2–10 mm.

Leaves

5–10(–13) cm;

stipules 8–22 × 2–5 mm, auricles flared, 2–5 mm, margins usually entire, sometimes erose or lobed, finely ciliolate to ciliate, eglandular, surfaces glabrous or sparsely pubescent, sparsely stipitate-glandular or eglandular;

petiole and rachis sometimes with pricklets, glabrous or hairy hairs to 1 mm, sometimes stipitate-glandular;

leaflets 5–7(–9), terminal: petiolule 8–12 mm, blade elliptic-ovate, (15–)20–45(–60) × 9–16(–20) mm, widest at or below middle, membranous, base cuneate to obtuse, margins 1(–2)-serrate, teeth 12–22 per side, on distal 3/4–4/5 of margin, acute, eglandular, apex acute, sometimes obtuse, abaxial surfaces pale green, usually sparsely pubescent, eglandular, adaxial green, dull, glabrous, rarely puberulent.

5–10 cm;

leaflets 5–7(–9), most commonly 7, terminal blade 15–35 mm.

Inflorescences

corymbs, sometimes panicles or solitary flowers, 1–12-flowered.

(1–)3–12-flowered.

Pedicels

erect, sometimes recurved, slender, 10–22 mm, usually glabrous, sometimes finely puberulent, eglandular, rarely stipulate-glandular;

bracts 2–3, lanceolate, 8–14 × 3–6 mm, margins entire, sometimes serrate, irregularly stipitate-glandular and/or erose, surfaces glabrous or pubescent, eglandular.

Flowers

2.4–3.8 cm diam.;

hypanthium ovoid-urceolate, 3–5 × 2.5–3.5 mm, glabrous, rarely setose, eglandular, neck (0–)0.5–1 × 2 mm;

sepals spreading, ovate-lanceolate, 10–17 × 1.5–3 mm, tip 3–7(–10) × 1.5–2.5 mm, margins entire, abaxial surfaces sometimes puberulent, densely or sparsely stipitate-glandular, rarely eglandular;

petals single, pink to deep pink, 12–18 × 10–18 mm;

stamens 75;

carpels 22–35, styles exsert 1–2 mm beyond stylar orifice (1 mm diam.) of hypanthial disc (3.5 mm diam.).

sepal tip to 10 mm, abaxial surfaces usually stipitate-glandular;

carpels 22–35.

Hips

scarlet, globose, sometimes subglobose or ovoid, 7–15 × 7–13 mm, fleshy, glabrous, eglandular, rarely setose- or stipitate-glandular, neck (0–)1–1.5 × 1.5–3.5 mm;

sepals persistent, erect.

usually globose, rarely subglobose, 7–10 mm diam., abruptly narrowed to neck 1.5–3 mm diam.

Achenes

basiparietal, 5–35, tan, 3–4 × 1.5–2.5 mm.

25–35.

2n

= 14, 28.

= 14.

Rosa pisocarpa

Rosa pisocarpa subsp. pisocarpa

Phenology Flowering Jun–Aug.
Habitat Coasts, stream banks, riparian areas, open and low places, sedge meadows, swamps, roadside hedges, thickets, montane oak belts
Elevation 30–2100 m (100–6900 ft)
Distribution
from FNA
CA; OR; WA; BC
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; OR; WA; BC
[BONAP county map]
Discussion

Subspecies 2 (2 in the flora).

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

Subspecies pisocarpa encompasses traditional circumscriptions of Rosa pisocarpa. It occurs in coastal regions from southwestern British Columbia to northern California, west of and within the Cascade Mountains. Stems tend to have paired erect prickles, stipitate-glandular sepals with elongate tips, and clusters of pea-shaped hips. Limited populations intermediate with R. woodsii subsp. ultramontana occur in Cascade Mountain passes along the Fraser River (British Columbia), the Columbia River (Oregon and Washington), and the Klamath River (southern Oregon). Reports of R. pisocarpa from farther east (for example, R. J. Davis 1952) were based on R. woodsii or other species.

The Snohomish and Squaxin of Puget Sound, Washington, used subsp. pisocarpa root decoctions to treat sore throats, and bark infusions for after child-birth, respectively (D. E. Moerman 1998). Southeastern Vancouver Island Saanich have used young shoots for food in the spring; ripe hips were eaten raw in the fall. They also boiled branches to make a decoction, which was used to flush the eyes of those not able to see well; this preparation served to treat any eye problem, including cataracts (N. J. Turner, pers. comm.).

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

Key
1. Inflorescences (1–)3–12-flowered; sepal abaxial surfaces usually stipitate-glandular, tips to 10 mm; infrastipular prickles (1–)2; hips usually globose, rarely subglobose, abruptly narrowed to necks 1.5–3 mm diam.; leaflets most commonly 7, terminal blade 15–35 mm.
subsp. pisocarpa
1. Inflorescences 1–3(–10+)-flowered; sepal abaxial surfaces usually eglandular, rarely stipitate-glandular, tips to 7 mm; infrastipular prickles 0–1(–2); hips subglobose to ovoid, gradually to abruptly narrowed to necks 2.5–3.5 mm diam.; leaflets most commonly 5, terminal blade 20–45(–60) mm.
subsp. ahartii
Source FNA vol. 9, p. 109. FNA vol. 9, p. 110.
Parent taxa Rosaceae > subfam. Rosoideae > tribe Roseae > Rosa > subg. Rosa > sect. Rosa Rosaceae > subfam. Rosoideae > tribe Roseae > Rosa > subg. Rosa > sect. Rosa > Rosa pisocarpa
Sibling taxa
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. rubiginosa, R. rugosa, R. setigera, R. sherardii, R. spinosissima, R. spithamea, R. stellata, R. tomentosa, R. virginiana, R. woodsii
R. pisocarpa subsp. ahartii
Subordinate taxa
R. pisocarpa subsp. ahartii, R. pisocarpa subsp. pisocarpa
Synonyms R. rivalis
Name authority A. Gray: Proc. Amer. Acad. Arts 8: 382. (1872) unknown
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