Jepson eFlora: Key page
Vascular Plants of California
Key to families | Table of families and genera
    Index to accepted names and synonyms:
| A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
   
   

Key to Rosaceae

View taxon page for Rosaceae

 

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

1. Annual to  herb

2. Plant 1–2 m; leaves 2–3-pinnately compound; flowers unisexualfruit  ..... ARUNCUS

2' Plant generally < 1 m; leaves  to 1-ternately or 1-palmately or 1-pinnately compound, including 2-ternately dissected; flowers generally fruit achenes or 

3. Petals 0, sepals generally 4; fruits 1(3) per flower, inside ±  

4. Leaf palmately lobed; inflorescence few-flowered cluster, , ± hidden by sheathing stipules not hardened in fruitannual ..... APHANES

4' Leaf pinnately compoundinflorescence  or  or terminal, not hidden;  ± hardened in fruit; generally  herb

5. Hypanthium ± prickly, not angled in fruitstamens 2 or 4 ..... ACAENA

5' Hypanthium not prickly, 4-angled in fruitstamens 0–many

6. Leaflets lobed > 2/3 to midvein; annualbiennial leaves withered at flower ..... POTERIDIUM

6' Leaflets toothed < 1/3 to midvein;  herb leaves not withered at flower

7. Largest   generally 5–20 mm, on stalk generally 1–4 mm, teeth generally < 15; stamens many, filaments thread-like; open, especially disturbed areas; CA-FP (except SNH) ..... POTERIUM

7' Largest   25–50 mm, on stalk 3–25 mm, teeth generally > 15; stamens 2–4, filaments not thread-like; bogs, streams; c NCo, nw KR, n NCoRO ..... SANGUISORBA

3' Petalssepals generally 5; fruits 1–many per flower, on or outside shallow to ± obconic 

8. Leaves ± 2-ternately dissectedsegments fruit  ..... LUETKEA (2)

8' Leaves  to compound, ternately compound or not but not ternately dissectedsegments  or not or 0; fruit achenes, sometimes fleshy-coated (Rubus) or on fleshy receptacle (Duchesnea, Fragaria)

9. Hypanthium obconic to cup-shaped, rim with hooked bristlesinflorescence ±  ..... AGRIMONIA

9' Hypanthium generally shallower than obconic to cup-shaped, rim without hooked bristlesinflorescence generally  or flowers 1

10. Hypanthium bractlets 0; achenes fleshy-coated, finely hairy ..... RUBUS (3)

10' Hypanthium bractlets generally present; achenes not fleshy-coated, generally glabrous (except Geum)

11. Style continuous to fruit, if not or inconspicuously hooked then  – leaves 1-pinnately compound ..... GEUM

11' Style jointed to fruit, not hooked, not hairy

12. Leaf (sub)palmately to ternately compound

13. Receptacle in fruit strawberry-like (enlarged, red, fleshy); stolons generally present; petals white or yellow; leaves ternately compound

14. Petals yellow; flowers 1 from axils of leaves on stolons bractlets generally wider than sepals ..... DUCHESNEA

14' Petals generally white; flowers 1–several from axils of  leavesstolons leafless;  bractlets narrower than sepals ..... FRAGARIA

13' Receptacle in fruit not strawberry-like; stolons 0; petals ± yellow; leaves pinnatelypalmately, or ternately compound

15. Stamens 5; petals ± 1 mm; leaflets 3, generally 3-toothed at tip ..... SIBBALDIA

15' Stamens 10–25; petals (2)4–20 mm; leaflets 3–7, generally > 3-toothed ..... POTENTILLA (2)

12' Leaf ± 1-pinnately to subpalmately compound

16. Petals dark red,  to ± , << sepals ..... COMARUM

16' Petals yellow to white,  to obcordate (linear), < to > sepals

17. Style , attached below fruit middle ..... DRYMOCALLIS

17' Style slender throughout or widest near base, generally attached below fruit tip

18. Hypanthium cup-like, ± flat-bottomed; filaments generally ± flat, often forming tubepetals white or ± pink

19. Stamens 10; leaflets 2–15 per side; CA-FP, GB ..... HORKELIA

19' Stamens 20; leaflets 15–35 per side; c&s SNH, SNE ..... HORKELIELLA

18' Hypanthium ± shallow, if cup-like, not flat-bottomed; filaments generally thread-like, not flat (except ± flat in Ivesia argyrocoma var. argyrocoma), not forming tubepetals white to yellow

20. Plant generally hanging clump or  in vertical rock crevices, ± resin-scented ..... IVESIA (2)

20' Plant not hanging clump or , generally not in vertical rock crevices, resin-scented or not

21. Leaf generally ± leaflets 4–80 per side; pistils 1–8(20); stamens 5–20(40); petals 1–5(7) mm,  to obovate or round ..... IVESIA (2)

21' Leaf generally ± flat; leaflets 2–8(13) per side; pistils generally > 10; stamens 20–25; petals (2)4–20 mm, generally ± widely obcordate ..... POTENTILLA (2)

1' Subshrub to tree

22. Leaves deeply lobed (generally to midrib) or compound

23. Ovary generally inferiorchambers 1–5; styles 1–5; fruit pome ..... SORBUS

23' Ovary superiorchamber 1; style 1; fruit  or follicle

24. Pistils generally 10–many

25. Petals yellow;  bractlets 5; style attached near fruit base ..... DASIPHORA

25' Petals white to red;  bractlets 0 (5 in Fallugia); style attached at fruit tip

26. Plant not prickly; leaves pinnately lobed, rusty-scaly abaxially, margins rolled under; style  in fruit; e DMtns ..... FALLUGIA

26' Plant generally prickly; leaves pinnately to palmately compound, not rusty-scaly, margins not generally rolled under; style short-hairy to ± glabrous in fruit; generally CA-FP, GB

27. Leaves pinnately compound fruit not on spongy receptacle, generally enclosed in fleshy hypanthium ..... ROSA

27' Leaves palmate-lobed or -compound;  flat to saucer-shaped; fruit on spongy receptacle, not enclosed by hypanthium (aggregate raspberry- or blackberry-like) ..... RUBUS (3)

24' Pistils 1–6

28. Leaves ; 1° leaflets 5–14 cm; inflorescence generally flat-topped; trunk bark peeling in strips; ChI ..... LYONOTHAMNUS (2)

28' Leaves  or clustered; 1° leaflets or  generally < 5 cm; inflorescence not flat-topped; trunk bark generally not peeling in strips; mainland

29. Leaf 3–9-lobed; inflorescence generally 1-flowered; styles in fruit 2–6 cm,  ..... PURSHIA (4)

29' Leaf (1)2–3-pinnate- or -ternate-dissected or -compound; inflorescence  or styles in fruit generally << 1 cm, not 

30. Stem ±  to ; plant < 2 dm; leaves ternately dissected, not glandular, not strong-smelling ..... LUETKEA (2)

30' Stem  to ; plant > 2 dm; leaves pinnately compoundglandular, strong-smelling

31. Pistil 1(2); ovule 1; fruit leaves 2–3-pinnately compound ..... CHAMAEBATIA

31' Pistils 4–5; ovules generally >= 2; fruit follicleleaves (1)2-pinnately compound ..... CHAMAEBATIARIA

22' Leaves , lobed (deeply so only in Crataegus monogyra) or unlobed

32. Ovary inferior or 1/2-inferior, chambers generally 2–5; fruitpome with generally papery core, occasionally drupe-like with 1–5 stones

33. Stem armed with thorns

34. Leaves ± deciduous, generally ± lobed above middle, toothed; larger leaves > 3 cm wide; fruit red to black ..... CRATAEGUS

34' Leaves generally oblanceolate, narrowly , narrowly obovate, or narrowly , ± evergreen, unlobed,  to toothed; larger leaves < 2.5 cm wide; fruit orange to red ..... PYRACANTHA

33' Stem generally not armed (thorny or not in Malus, Pyrus)

35. Leaf generally sharp-toothed

36. Inflorescence many-flowered petals < 4 mm; fruit 5–10 mm diam ..... HETEROMELES

36' Inflorescence few-flowered cluster; petals 10–15 mm; fruit >= 10 mm diam

37. Fruit generally ± spheric, flesh not gritty ..... MALUS

37' Fruit generally ± obovoid, flesh gritty ..... PYRUS

35' Leaf , minute-gland-toothed, or above middle toothed

38. Leaves ± clustered on short-shoots,  ± 0 ..... PERAPHYLLUM

38' Leaves evenly distributed on branches, twigs > ± 0

39. Leaves generally  above middle, deciduousfruitpome of 2–5 papery segments, generally blue-black ..... AMELANCHIER

39' Leaves deciduous, or evergreenfruitpome, drupe-like with 2–5 stones, orange to red..... COTONEASTER

32' Ovary superior (sometimes hidden in funnel- or  hypanthium), chamber generally 1; fruit not a pome

40. Leaf veins 

41. Leaf  3(5)-lobed above middle, generally wedge-shaped, margin not toothed, rolled under; flowers 1 ..... PURSHIA (4)

41' Leaf  generally 3–7-lobed below middle, not wedge-shaped, margin ± toothed, ± flat; flowers in cluster of several to many

42. Petals 2.5–3 mm; pistils 1–5 (if 3–5, fused below middle); inflorescence umbel-like cluster, not flat-topped; fruit  ..... PHYSOCARPUS

42' Petals 4–30 mm; pistils 5–150; inflorescence raceme- or panicle-like , ± flat-topped; fruit fleshy-coated achenes (aggregate ± raspberry-like) ..... RUBUS (3)

40' Leaf veins 

43. Plant matted,  many – generally on limestone ..... PETROPHYTUM

43' Erect shrub or tree, not  0

44. Leaves  or in opposite clusters

45. Shrub 2–20 dm; petals 0 (1–5); pistil 1(2); fruit ; SNE, D (especially DMtns) ..... COLEOGYNE

45' Tree 40–150 dm; petals 5; pistils 2; fruit follicle; ChI ..... LYONOTHAMNUS (2)

44' Leaves  or in alternate clusters

46. Pistil generally 1

47. Hypanthium cup- to deciduous in fruitstyle not  to stigma; fruit drupe ..... PRUNUS

47' Hypanthium ±  to obconic, persistent in, ± enclosing fruitstyle  to stigma; fruit  or achene-like

48. Hypanthium 0.6–3.2 mm; petals 1.5–2.5 mm; inflorescence many-flowered   to oblanceolate or sickle-shaped, margin not rolled under ..... ADENOSTOMA

48' Hypanthium 2–14 mm; petals 0 or 6–8 mm; inflorescence 1–18-flowered cluster;   to round, margin generally rolled under

49. Petals 0;  toothed or not,  0 ..... CERCOCARPUS

49' Petals 6–8 mm, white to cream;  generally not toothed,  3–9 ..... PURSHIA (4)

46' Pistils generally 2–6

50. Leaf generally inflorescence pendent; flowers unisexual, occasionally fruit drupes ..... OEMLERIA

50' Leaf lobed or toothed; inflorescence umbel-like cluster, , or flower 1,  to ; flowers fruit achenes or 

51. Leaf generally widest above middle, margins with 3–9 , generally 0 teeth, ± strongly rolled under; flowers 1 ..... PURSHIA (4)

51' Leaf generally widest at or below middle, margins with ± 0 , generally with teeth, not rolled under; flowers generally 3–many

52. Inflorescence umbel-like cluster, flowers generally 3–5; petals 4–6 mm; stamens ± 50, sepals ± toothed ..... NEVIUSIA

52' Inflorescence  or , flowers many; petals 1.5–2 mm; stamens generally < 50, sepals not toothed

53. Petals generally white;  saucer-shaped; stigma ± 2-lobed; fruitachenes ..... HOLODISCUS

53' Petals pink to rose;  obconic to bell-shaped; stigma head-like; fruit ..... SPIRAEA

 

Contact/Feedback

Citation for the whole project: Jepson Flora Project (eds.) . Jepson eFlora, http://ucjeps.berkeley.edu/eflora/ [accessed on ]

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

We encourage links to these pages, but the content may not be downloaded for reposting, repackaging, redistributing, or sale in any form, without written permission from The Jepson Herbarium.