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Key to Erigeron

View taxon page for Erigeron

(For a list of species in Erigeron, use the above link.)

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

1. Heads discoid, disciform, or inconspicuously radiaterays 0 to barely exceeding 

2. Pistillate flowers present

3. Pistillate flowers of 2 kinds, those in outer zone with rays 3–4.5 mm, those in inner zone without rays ..... E. nivalis (2)

3' Pistillate flowers ± all alike, generally not in 2 zones

4. Heads 1; stem 

5. Annual or biennialpappus bristles 6–9(12) ..... E. divergens (3)

5' Perennial herbpappus bristles 12–25

6. Leaves (1)2–3(4)-ternately dissected ..... E. compositus (2)

6' Leaves 

7. Stem minutely glandular; disk corolla generally abruptly inflated to throatfruit base ringed ± white; outer pappus of narrow scales or obvious bristles ..... E. aphanactis var. congestus

7' Stem glandless; disk corolla narrowly fruit base ringed ± yellow; outer pappus of minute bristles ..... E. chrysopsidis var. austiniae

4' Heads 1–many; stem often branched

8. Rays 1–3 mm

9. Inflorescence panicle-like, heads many; rays <= 1 mm;  glabrous or sparsely  to minutely bristly; central colored part of middle phyllaries resin-filled, ± red-brown when dry ..... E. canadensis (3)

9' Inflorescence generally raceme-like, heads 1–12; rays 2–3 mm;  ± rough-hairy; central colored part of middle phyllaries not resin-filled, not red-brown when dry ..... E. lonchophyllus (2)

8' Rays 0–1 mm

10. Central stem and axes of stiffly  branches generally strongly dominant; inflorescence generally raceme- or panicle-like, often many-headed; disk flowers 6–25

11. Central stem often overtopped by distal branches in age; plant ± gray-hairy; heads ± long-peduncled, generally in raceme-like clusters; receptacle (2.5)3–5 mm diam in fruitpistillate flowers 60–150+; phyllaries generally minutely bristly and/or densely pappus 3–4+ mm ..... E. bonariensis

11' Central stem generally exceeding distal branches in age; plant green, glabrous to hairy; heads ± short-peduncled in panicle-like clusters; receptacle 1–3 mm diam in fruitpistillate flowers 20–90+; phyllaries glabrous to densely  or densely bristly; pappus 2–3(4) mm

12. Leaf ± long-bristly-ciliate; phyllaries generally glabrous, occasionally sparsely ; central colored part of middle phyllaries narrower than light-colored margin, resin-filled, ± red-brown when dry; ray 0.3–1 mm; disk corolla generally 4-lobed; fruit uniformly pale tan to light gray-brown ..... E. canadensis (3)

12' Leaf margin generally ± fine-strigose; phyllaries glabrous to densely  or spreading-hairy; central part of middle phyllaries generally wider than lighter margin, not red-brown or resin-filled when dry; ray 0–0.3 mm; disk corolla generally 5-lobed; fruit pale tan, generally some in  with ± red veins ..... E. sumatrensis

10' Central stem and axes of  branches not strongly dominant, plant ± openly branched; inflorescence ± cyme-like, often 1–few-headed; disk flowers generally >= 25

13. Perennial herbpappus bristles 12–17 ..... E. aphanactis var. aphanactis

13' Annualbiennial or short-lived  herbpappus bristles 6–9(12) or 15–20

14. Pappus bristles 15–20; biennial or short-lived  herb ..... E. calvus

14' Pappus bristles 6–9(12); annual or biennial ..... E. divergens (3)

2' Pistillate flowers 0

15. Basal leaves present at flower; cauline leaves generally much-reduced or 0 distally

16. Caudex  ..... E. lassenianus var. deficiens

16' Caudex branched

17. Stem , 15–40 cm, occasionally sparsely spreading-hairy;  branches slender, rhizome-like;  leaves  to oblanceolate to spoon-shaped ..... E. supplex

17' Stem , 4–15 cm, ± glabrous to densely  branches short, stout leaves ±  ..... E. bloomeri

18. Herbage and phyllaries  ..... var. bloomeri

18' Herbage and phyllaries ± glabrous ..... var. nudatus

15' Basal leaves 0 at flower; cauline leaves generally evenly sized and spaced

19. Glandless stem hairs ± 

20. Stem hairs dense, short, stiff, slightly , ± gray ..... E. inornatus var. keilii

20' Stem hairs sparse to dense, long, ± crinkly-spreading, white

21. Stem 30–90 cm,  to leaves 20–40 mm;  12–15 mm diam ..... E. biolettii (2)

21' Stem 5–30 cm,  to leaves 7–25 mm;  7–15 mm diam

22. Inner phyllaries 3.5–5 mm ..... E. miser

22' Inner phyllaries 5.5–7 mm ..... E. petrophilus

23. Herbage ± glandless; hairs stiff, straight or curved ..... var. viscidulus

23' Herbage densely glandular; glandless hairs generally loose, often crinkly

24. Phyllary tips obviously widened and ± purple ..... var. petrophilus

24' Phyllary tips not widened or purple ..... var. sierrensis

19' Glandless stem hairs 0–sparse, 

25. Phyllaries generally glabrous ..... E. inornatus (in part)

26. Stem 10–20 cm,  to proximally ± reflexed-hairy; proximal and middle  blades and margins stiffly spreading-hairy and -ciliate; inner phyllaries 5–6.5 mm ..... var. calidipetris

26' Stem 30–90 cm, proximally ± glabrous or appressed-hairy; proximal and middle  blades and margins generally short-strigose or ± glabrous; inner phyllaries 4.5–5.5 mm ..... var. inornatus

25' Phyllaries glandular (sometimes also with sparse, glandless hairs)

27. Herbage glandular narrowly oblanceolate ..... E. biolettii (2)

27' Herbage glandless;  thread-like to oblanceolate

28. Leaf ± oblanceolate; stem long-ascending from woody taproot ..... E. inornatus var. inornatus

28' Leaf thread-like to stem from stout woody  or thin, rhizome-like caudex branches

29. Stem 30–90 cm, many, from stout woody  ..... E. greenei

29' Stem 8–20(30) cm, 1, from slender, rhizome-like  branches ..... E. reductus

30. Phyllary tips generally ± purple (variable n SnFrB); pappus bristles 38–61 ..... var. angustatus

30' Phyllary tips ± green; pappus bristles 20–30 ..... var. reductus

1' Heads conspicuously radiaterays exceeding to much-exceeding 

31. Pistillate flowers of 2 kinds, those in outer zone with rays 3–4.5 mm, those in inner zone without rays ..... E. nivalis (2)

31' Pistillate flowers all alike, not in 2 zones

32. Rays 1–3 mm

33. Inflorescence panicle-like, heads many; rays <= 1 mm;  glabrous or sparsely  to minutely bristly; central colored part of middle phyllaries resin-filled, ± red-brown when dry ..... E. canadensis (3)

33' Inflorescence generally raceme-like, heads 1–12; rays 2–3 mm;  ± rough-hairy; central colored part of middle phyllaries not resin-filled, not red-brown when dry ..... E. lonchophyllus (2)

32' Rays 4–25 mm

34. Annual (biennial to short-lived  herb) from slender taproot or shallow  roots (see also Erigeron philadelphicus var. philadelphus)

35. Ray flower pappus 0; plant fibrous-rooted

36. Leaves generally coarsely toothed; stem hairs sparsely  or  ..... E. annuus

36' Leaves generally stem hairs  ..... E. strigosus var. strigosus

35' Ray flower pappus present; plant taprooted (Erigeron flagellaris generally fibrous-rooted)

37. Stem hairs ; plant with herbaceous, leafy runners ..... E. flagellaris

37' Stem hairs ; plant without runners ..... E. divergens (3)

34' Perennial herb or subshrub from woody taproot, branched , or 

38. Leaves 1–4-ternately dissected

39. Leaves generally (1)2–3(4)-ternately dissected; ray < 1 mm wide;  branches short, thick,  ..... E. compositus (2)

39' Leaves deeply 3-lobed at tip; ray 1–2 mm wide;  branches thin, rhizome-like ..... E. vagus

38' Leaves  to shallowly toothed

40. Leaf bases hardened, white-shiny, expanded, enclosing proximal stem

41. Caudex branches thick,  bases persistentrays yellow ..... E. linearis

41' Caudex branches slender, rhizome-like,  bases not persistentrays white, pink to blue or lavender

42. Involucre 13–18 mm diam;  leaves generally 2–5 mm wide; pappus bristles 25–40; phyllary hairs ; >= 2100 m; CaRH, n&c SNH ..... E. barbellulatus

42' Involucre 6–11 mm diam;  leaves generally 0.5–1 mm wide; pappus bristles 20–30; phyllary hairs ; 1000–2200 m; MP ..... E. elegantulus

40' Leaf bases ± thin, not hardened, barely or not expanded

43. Fruit ribs 4–8; herbage generally ± silvery, hairs dense

44. Fruit ribs 6–8;  leaves tufted, persistent ..... E. argentatus

44' Fruit ribs 4(6);  leaves generally 0 at flower

45. Outer pappus conspicuous, of bristles or narrow scalesstem silvery-white ..... E. parishii

45' Outer pappus inconspicuous; stem gray-green, densely  ..... E. utahensis

43' Fruit ribs generally 2 (if more, herbage not silvery)

46. Phyllaries strongly graduatedleaves , not clasping,  0, cauline generally evenly sized and spaced

47. Stem minutely glandular ..... E. aequifolius

47' Stem generally not glandular

48. Stem hairs dense, minutely curled- or bent; fruit glabrous ..... E. blochmaniae

48' Stem hairs 0 to dense, straight, stiffly  to ±  or fruit sparsely 

49. Stem hairs dense, stiffly , generally slightly 

50. Herbage hairs 0.5–1 mm; phyllaries densely minutely glandular, inner phyllary tips widely white-thick-margined; stem often from woody  offsets and roots ..... E. klamathensis

50' Herbage hairs <= 0.1–0.4 mm; phyllaries glandular or glandless, inner phyllary tips green; stem from ± slender, rhizome-like bases ..... E. breweri

51. Phyllaries densely glandular, glandless hairs 0 or very sparse

52. Stem generally >= 20 cm,  to leaves generally >= 15 mm ..... var. breweri

52' Stem 7–15 cm,  to leaves 5–12 mm ..... var. jacinteus

51' Phyllaries not or barely glandular, glandless hairs prominent

53. Stem 20–30 cm, wiry, brittle; phyllary hairs long, thick-based, stiffly , translucent (also some glandular) ..... var. porphyreticus

53' Stem 30–75 cm, not wiry or brittle; phyllary hairs short, white, ± , glandless

54. Phyllary hairs thin-based, ± , slightly less dense on inner phyllaries ..... var. bisanctus

54' Phyllary hairs thick-based, , much less dense on middle and inner phyllaries ..... var. covillei

49' Stem hairs ± 0 or sparse, 

55. Stem  to ± , from slender  ..... E. elmeri

55' Stem  to , from woody taproot

56. Ray flowers 9–13;  hairs thin-based; phyllaries with minute glandless hairs and densely minutely glandular ..... E. serpentinus

56' Ray flowers 15–60;  hairs thick-based; phyllaries glandular or glandless

57. Phyllaries ± glandless, 0.5–0.8 mm wide, margins generally thick to ± scarious

58. Leaves 2–4(5) cm, oriented variously; inner phyllaries 3.2–4.5 mm ..... E. foliosus var. foliosus

58' Leaves (2.5)4–6(8) cm, often ± oriented to 1 side of stem; inner phyllaries (4)5–6 mm

59. Stem 30–85 cm;   tufts 0; leaves 35–80 mm, 1–2(4) mm wide; inner phyllaries not strongly scarious; ray flowers 26–50 ..... E. foliosus var. hartwegii

59' Stem 15–28 cm;   tufts generally present; leaves 25–45 mm, (2)5–8 mm wide; inner phyllary margins strongly scarious; ray flowers 18–22 ..... E. mariposanus

57' Phyllaries minutely but prominently glandular, 0.8–1 mm wide, margins generally widely scarious ..... E. foliosus (in part)

60. Phyllary hairs all glandularleaves generally 1–2 mm wide ..... var. confinis

60' Phyllary hairs glandular and glandless, ± densely bristly-strigose; leaves generally 2–4 mm wide

61. Leaf blades ± phyllary midvein raised, orange-resinous; ray corolla 7–10 mm ..... var. franciscensis

61' Leaf blades ± glabrous (except  hairs); phyllary midvein generally not raised or orange-resinous; ray corolla 10–15 mm ..... var. mendocinus

46' Phyllaries generally ± equal; leaves  to lobed, sometimes clasping,  sometimes present, cauline often strongly reduced distally on stem, if present

62. Plant fibrous-rooted, generally from obvious  or ±  cauline leaves often ± clasping;

63. Glandless phyllary hairs with black cross-walls (sometimes only on  cells of hairs)

64' Rays blue to purple ..... E. sanctarum (2)

63' Glandless phyllary hairs 0 or with clear cross-walls

65' Ray flowers 20–165 (80–300+ in E. glaucus)

66. Leaves thick, ± fleshy or toothed; coastal ..... E. glaucus

66' Leaves ± thin, ; coastal or inland

67. Glandless phyllary hairs prominent, glandular hairs sometimes present

68. Stem from thin, often stolon-like  branches with few  roots ..... E. sanctarum (2)

68' Stem from short, thick, strongly fibrous-rooted  or 

69. Stem 2–20(30) cm, hairs phyllaries ± black-purple; pappus bristles 12–16(20) ..... E. algidus (2)

69' Stem 30–100 cm, hairs phyllaries ± green; pappus bristles 20–30 ..... E. aliceae (2)

67' Glandless phyllary hairs 0, glandular hairs dense

70. Stem glabrous or sparsely minutely glandular; ray flowers 20–30(45) ..... E. cervinus

70' Stem ± appressed-hairy, sometimes also ± bristly; ray flowers 30–105

71. Fruit 2(4)-ribbed, moderately to densely proximal leaves generally coarsely , sometimes  ..... E. aliceae (2)

71' Fruit 4–7-ribbed, sparsely proximal leaves  ..... E. glacialis

72. Peduncles densely minutely  with loosely , slightly crinkled hairs ..... var. glacialis

72' Peduncles bristly or ± stiffly long-soft-hairy ..... var. hirsutus

62' Plant taprooted or with taprooted cauline leaves not at all clasping

73. Stem spreading- or reflexed-hairy

74. Leaf clearly petioled,  oblanceolate, , obovate to spoon-shaped

75. Basal leaves 20–70 mm; cauline leaves much reducedstem 2–30 cm; phyllaries ± black-purple; ray flowers (30)50–125, ray 7–13 mm ..... E. algidus (2)

75' Basal leaves 5–25 mm; cauline leaves 0; stem 1–4 cm; phyllaries green; ray flowers 15–40, ray 4–6 mm ..... E. uncialis var. uncialis

74' Petiole indistinct,   or oblanceolate, gradually  to base

76. Margins of proximal leaves generally hairy but not stiffly spreading-ciliate; generally > 2200 m

77. Basal leaves 20–80 mm; stem sparsely minutely glandular at least distally, and moderately hairy with short, stiffly  to , glandless hairsphyllaries green; ray flowers 25–55, ray 6–11 mm ..... E. clokeyi var. pinzliae

77' Basal leaves 6–35 mm; stem densely minutely glandular, also with short-stiff and ±  glandless hairsphyllaries ± black-purple; ray flowers 20–37, ray 4–7(10) mm ..... E. pygmaeus

76' Margins of proximal leaves generally stiffly long-spreading-ciliate; 1200–1800 m

78. Disk corolla (±) glabrouspappus bristles 12–22; outer pappus of inconspicuous bristles or narrow scalesrays (40)55–115, 8–12 mm ..... E. pumilus var. intermedius

78' Disk corolla sharply scabrouspappus bristles 5–15; outer pappus of prominent wide scalesrays 40–60, 7–9 mm ..... E. concinnus var. concinnus

73' Stem glabrous or ascending- to appressed-hairy (to ± spreading-hairy in Erigeron lassenianus)

79. Ray flowers 75–125; disk corolla throat ± widened ..... E. multiceps

79' Ray flowers generally 14–80; disk corolla ± narrowly 

80. Basal leaves 0 at flower

81. Leaves sharply reduced distally on stem  tufts 0; ray flowers 12–27(45) ..... E. oxyphyllus

81' Only most distal cauline leaves reduced tufts in axils; ray flowers 45–80 ..... E. karvinskianus

80' Basal leaves generally persistent

82. Basal leaves thread-like to 

83. Stem 2–8 cm, leafless; stem hairs straight,  leaves 5–25 mm; fruit ribs densely , faces glabrous ..... E. compactus

83' Stem 15–30 cm, generally leafy, at least proximallystem hairs curved up, ± loose;  leaves generally 20–70 mm; fruit ribs and faces sparsely hairy ..... E. filifolius

82' Basal leaves narrowly oblanceolate to  or spoon-shaped (or  in Erigeron lassenianus var. lassenianus and Erigeron robustior)

84. Plants  stout, branched;  leaves oblanceolate to , petioled; cauline leaves abruptly reduced ..... E. tener

84' Plants not  generally slender;  leaves  to narrowly oblanceolate,  indistinct; cauline leaves gradually reduced

85. Basal leaves generally persistentcauline leaves generally smaller than heads 1–4(7) ..... E. eatonii

86. Involucre (14)17–23 mm diam; longest phyllaries 7–11 mm; disk corolla 4.4–6.8 mm ..... var. nevadincola

86' Involucre 8–16 mm diam; longest phyllaries 5–8 mm; disk corolla 3–5 mm

87. Stem 10–23 cm; disk corolla 3–4 mm; pappus bristles 16–20, 3–3.5 mm ..... var. plantagineus

87' Stem 4–12(21) cm; disk corolla 3.5–5 mm; pappus bristles 18–30, 3.5–5 mm ..... var. sonnei

85' Basal leaves persistent at, or withering before, flower; cauline leaves gradually or little reducedheads (1)2–7(18)

88. Phyllaries densely minutely glandular 4–5.5 mm, 6–10(12) mm wide; leaves generally 1-veined ..... E. lassenianus var. lassenianus

88' Phyllaries generally glandless;  generally 6–8.5 mm, (9)12–20 mm wide; leaves generally 3-veined

89. Plants 10–22(27) cm; taproots ± thick, (3)5–8 mm wide;  leaves oblanceolate to ± narrowly spoon-shaped; cauline leaves ± continuing to headsinvolucres (5)6–7 mm, 9–12(14) mm wide; phyllaries elliptic-oblanceolate to oblong-oblanceolate, abruptly  ..... E. maniopotamicus

89' Plants (15)25–55 cm; taproots ± thin, 2–3 mm wide;  leaves  to very narrowly oblanceolate; cauline leaves ending ± well below headsinvolucres 6–8.5 mm, (12)14–20 mm wide; phyllaries narrowly oblanceolate to , acute-acuminate ..... E. robustior

 

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