Jepson eFlora
Key to families | Table of families and genera

Key to Rosa

View taxon page for Rosa

Jepson Manual glossary definitions can be seen by moving your cursor over words underlined with dots.

1. Leaflets << 1 cm, toothed ± 1/2 to base; hypanthium densely prickly — Peninsular Ranges ..... R. minutifolia

1' Leaflets generally > 1 cm, toothed < 1/4 to base; hypanthium glabrous to stalked-glandular

2. Sepals with toothed lateral lobes; prickles compressed side-to-side, curved

3. Hypanthium 1–2 mm wide at flower, 5–7 mm wide at fruit; pistils generally < 10 ..... R. multiflora

3' Hypanthium 4–5 mm wide at flower, 10–20 mm wide at fruit; pistils > 10

4. Leaves and sepals ± glandless; petals white to pink; terminal leaflet ± ovate ..... R. canina

4' Leaves and sepals glandular; petals pink; terminal leaflet generally elliptic to ± widely obovate ..... R. rubiginosa

2' Sepals generally entire (tip sometimes toothed); prickles compressed or slender, straight or curved

5. Sepals deciduous in fruit; hypanthium 1.5–2 mm wide at flower; pistils 5–10; sepal tip generally << body; petals ± 10 mm — leaflets glabrous, flowers 1–3; pedicels generally stalked-glandular ..... R. gymnocarpa

6. Leaflets generally (5)7–9; terminal leaflet tip generally ± obtuse, ± 10–30 mm; pedicels ± 15–30 mm; plants to ± 5–20 dm, generally in shade on non-ultramafic substrates; widespread ..... var. gymnocarpa

6' Leaflets generally 5(7); terminal leaflet tip widely obtuse to rounded, 4–20 mm; pedicels ± 10–15 mm; plants to generally 3–6 dm, full sun on ultramafic substrates; Klamath Ranges ..... var. serpentina

5' Sepals persistent; hypanthium 2.5–7 mm wide at flower; pistils generally > 10; sepal tip ± = or often > body; petals 10–25 mm

7. Dwarf, openly rhizomed shrubs, generally 1–5(10) dm; leaflet tip often ± truncateleaf margins generally ± glandular, generally double-toothed

8. Hypanthium stalked-glandular — prickles generally ± slender, often many; Northwestern California, Central Western California, Modoc Plateau(1 site), 150–1550(1950) m ..... R. spithamea

8' Hypanthium generally glandless, rarely sparsely glandular

9. Prickles few, paired, ± thick-based; terminal leaflet generally widely obovate; flower 1–2(7); Cascade Range, Sierra Nevada, 700–2500 m ..... R. bridgesii

9' Prickles generally many, generally not paired, both slender and ± thick-based; terminal leaflet generally ± elliptic; flowers generally 1–5; Central Western California, generally < 300 m ..... R. pinetorum

7' Open or thicket-forming shrubs, generally > 5 dm; leaflet tip not truncate

10. Terminal leaflet ± obovate-elliptic, widest at or above middle; leaf axis finely velvety, hairs ± 0.1 mm (glabrous), glandless; prickles slender to ± thick-based, generally ± straight; sepals glandless (in California); High Cascade Range, High Sierra Nevada, Tehachapi Mountain Area, Transverse Ranges, Great Basin Floristic Province, Desert Mountains ..... R. woodsii

11. Prickles generally many, 2–10(13) mm, often ± thick-based, internodal prickles generally present in inflorescence; c&s High Sierra Nevada, Tehachapi Mountain Area, Transverse Ranges, East of Sierra Nevada, Desert Mountains, s Mojave Desert exc Desert Mountains (Box S Springs, Cushenbury Springs) ..... subsp. gratissima

12. Leaf axis finely velvety; c&s High Sierra Nevada, Tehachapi Mountain Area, Transverse Ranges, East of Sierra Nevada, Desert Mountains ..... var. gratissima

12' Leaf axis glabrous; s Mojave Desert exc DMtn (Box S Springs, Cushenbury Springs) ..... var. glabrata

11' Prickles few to many, 2–7 mm, slender, internodal prickles generally 0 in inflorescence; High Cascade Range, n High Sierra Nevada, Modoc Plateau, n East of Sierra Nevada ..... subsp. ultramontana

10' Terminal leaflet generally ovate to elliptic, generally widest at or below middle; leaf axis variously hairy, hairs to 1 mm, sometimes glandular; prickles generally ± thick-based, often curved; sepals often glandular; California Floristic Province, adjacent Mojave Desert

13. Flowers generally 1(6); hypanthium generally 5–7 mm wide at flower, (10)13–20 mm wide at fruit, generally ± spheric; achenes generally 4.5–6 mm — prickles to 20 mm, generally ± compressed, ± straight to ± curved; sepal tips generally > body, toothed ..... R. nutkana

14. Leaflets generally ± single-toothed, generally glandless; prickles generally few; Outer North Coast Ranges, Klamath Ranges, High Cascade Range; 750–1500 m ..... subsp. macdougalii

14' Leaflets double-toothed, ± glandular especially beneath; prickles generally many; North Coast, Outer North Coast Ranges, Central Coast; < 700 m ..... subsp. nutkana

13' Flowers 1–many; hypanthium 2.5–5.5 mm wide at flower, 7–15(20) mm wide at fruit, spheric to (ob)ovoid; achenes 3–5 mm

15. Prickles generally thick-based, generally curved (straight), few to many; leaflets and leaf axis generally ± shaggy-hairy, hairs to 1 mm; pedicel generally ± hairy; hypanthium generally (ob)ovoid, glabrous to sparsely hairy, neck 2–4.5 mm wide at flower ..... R. californica

15' Prickles slender to ± thick-based, straight (± curved), 0–few; leaflets and leaf axis ± glabrous to ± hairy, hairs 0.1–1 mm; pedicels generally glabrous (except for glands); hypanthium spheric to ovoid, glabrous, neck ± 2 mm wide at flower ..... R. pisocarpa

16. Flowers 1–3(10); sepals generally glandless; prickles 0 to paired at nodes; leaflets generally 5(7) ..... subsp. ahartii

16' Flowers (1)3–10; sepals generally glandular; prickles generally paired at nodes; leaflets generally (5)7(9) ..... subsp. pisocarpa


Citation for the whole project: Jepson Flora Project (eds.) [year] Jepson eFlora, [accessed on month, day, year]
Citation for an individual treatment: [Author of taxon treatment] [year]. [Taxon name] in Jepson Flora Project (eds.) Jepson eFlora, [URL for treatment]. Accessed on [month, day, year].
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