1	"Heads discoid, disciform, or inconspicuously radiate, rays 0 to barely exceeding involucre"	2
1	"Heads conspicuously radiate, rays exceeding to much-exceeding involucre"	31
2	"Pistillate flowers present"	3
2	"Pistillate flowers 0"	15
3	"Pistillate flowers of 2 kinds, those in outer zone with rays 3--4.5 mm, those in inner zone without rays"	"Erigeron nivalis"
3	"Pistillate flowers +- all alike, generally not in 2 zones"	4
4	"Heads 1; stem simple"	5
4	"Heads 1--many; stem often branched"	8
5	"Annual or biennial; pappus bristles 6--9(12)"	"Erigeron divergens"
5	"Perennial herb; pappus bristles 12--25"	6
6	"Leaves (1)2--3(4)-ternately dissected"	"Erigeron compositus"
6	"Leaves entire"	7
7	"Stem minutely glandular; disk corolla generally abruptly inflated to throat; fruit base ringed +- white; outer pappus of narrow scales or obvious bristles"	"Erigeron aphanactis var. congestus"
7	"Stem glandless; disk corolla narrowly funnel-shaped; fruit base ringed +- yellow; outer pappus of minute bristles"	"Erigeron chrysopsidis var. austiniae"
8	"Rays 1--3 mm"	9
8	"Rays 0--1 mm"	10
9	"Inflorescence panicle-like, heads many; rays <= 1 mm; involucre glabrous or sparsely strigose to minutely bristly; central colored part of middle phyllaries resin-filled, +- red-brown when dry"	"Erigeron canadensis"
9	"Inflorescence generally raceme-like, heads 1--12; rays 2--3 mm; involucre +- rough-hairy; central colored part of middle phyllaries not resin-filled, not red-brown when dry"	"Erigeron lonchophyllus"
10	"Central stem and axes of stiffly ascending branches generally strongly dominant; inflorescence generally raceme- or panicle-like, often many-headed; disk flowers 6--25"	11
10	"Central stem and axes of ascending branches not strongly dominant, plant +- openly branched; inflorescence +- cyme-like, often 1--few-headed; disk flowers generally >= 25"	13
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 fruit; pistillate flowers 60--150+; phyllaries generally minutely bristly and/or densely strigose; pappus 3--4+ mm"	"Erigeron 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 fruit; pistillate flowers 20--90+; phyllaries glabrous to densely strigose or densely bristly; pappus 2--3(4) mm"	12
12	"Leaf +- long-bristly-ciliate; phyllaries generally glabrous, occasionally sparsely strigose; 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"	"Erigeron canadensis"
12	"Leaf margin generally +- fine-strigose; phyllaries glabrous to densely strigose 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 head with +- red veins"	"Erigeron sumatrensis"
13	"Perennial herb; pappus bristles 12--17"	"Erigeron aphanactis var. aphanactis"
13	"Annual, biennial or short-lived perennial herb; pappus bristles 6--9(12) or 15--20"	14
14	"Pappus bristles 15--20; biennial or short-lived perennial herb"	"Erigeron calvus"
14	"Pappus bristles 6--9(12); annual or biennial"	"Erigeron divergens"
15	"Basal leaves present at flower; cauline leaves generally much-reduced or 0 distally"	16
15	"Basal leaves 0 at flower; cauline leaves generally evenly sized and spaced"	19
16	"Caudex simple"	"Erigeron lassenianus var. deficiens"
16	"Caudex branched"	17
17	"Stem ascending, 15--40 cm, occasionally sparsely spreading-hairy; caudex branches slender, rhizome-like; basal leaves elliptic to oblanceolate to spoon-shaped"	"Erigeron supplex"
17	"Stem erect, 4--15 cm, +- glabrous to densely strigose; caudex branches short, stout; basal leaves +- linear"	18
18	"Herbage and phyllaries strigose"	"Erigeron bloomeri var. bloomeri"
18	"Herbage and phyllaries +- glabrous"	"Erigeron bloomeri var. nudatus"
19	"Glandless stem hairs +- spreading"	20
19	"Glandless stem hairs 0--sparse, appressed"	25
20	"Stem hairs dense, short, stiff, slightly reflexed, +- gray"	"Erigeron inornatus var. keilii"
20	"Stem hairs sparse to dense, long, +- crinkly-spreading, white"	21
21	"Stem 30--90 cm, ascending to erect; leaves 20--40 mm; involucre 12--15 mm diam"	"Erigeron biolettii"
21	"Stem 5--30 cm, decumbent to ascending; leaves 7--25 mm; involucre 7--15 mm diam"	22
22	"Inner phyllaries 3.5--5 mm"	"Erigeron miser"
22	"Inner phyllaries 5.5--7 mm"	23
23	"Herbage +- glandless; hairs stiff, straight or curved"	"Erigeron petrophilus var. viscidulus"
23	"Herbage densely glandular; glandless hairs generally loose, often crinkly"	24
24	"Phyllary tips obviously widened and +- purple"	"Erigeron petrophilus var. petrophilus"
24	"Phyllary tips not widened or purple"	"Erigeron petrophilus var. sierrensis"
25	"Phyllaries generally glabrous"	26
25	"Phyllaries glandular (sometimes also with sparse, glandless hairs)"	27
26	"Stem 10--20 cm, decumbent to ascending; proximally +- reflexed-hairy; proximal and middle leaf blades and margins stiffly spreading-hairy and -ciliate; inner phyllaries 5--6.5 mm"	"Erigeron inornatus var. calidipetris"
26	"Stem 30--90 cm, ascending; proximally +- glabrous or appressed-hairy; proximal and middle leaf blades and margins generally short-strigose or +- glabrous; inner phyllaries 4.5--5.5 mm"	"Erigeron inornatus var. inornatus"
27	"Herbage glandular; leaf narrowly oblanceolate"	"Erigeron biolettii"
27	"Herbage glandless; leaf thread-like to oblanceolate"	28
28	"Leaf +- oblanceolate; stem long-ascending from woody taproot"	"Erigeron inornatus var. inornatus"
28	"Leaf thread-like to linear; stem from stout woody caudex or thin, rhizome-like caudex branches"	29
29	"Stem 30--90 cm, many, from stout woody caudex"	"Erigeron greenei"
29	"Stem 8--20(30) cm, 1, from slender, rhizome-like caudex branches"	30
30	"Phyllary tips generally +- purple (variable n SnFrB); pappus bristles 38--61"	"Erigeron reductus var. angustatus"
30	"Phyllary tips +- green; pappus bristles 20--30"	"Erigeron reductus var. reductus"
31	"Pistillate flowers of 2 kinds, those in outer zone with rays 3--4.5 mm, those in inner zone without rays"	"Erigeron nivalis"
31	"Pistillate flowers all alike, not in 2 zones"	32
32	"Rays 1--3 mm"	33
32	"Rays 4--25 mm"	34
33	"Inflorescence panicle-like, heads many; rays <= 1 mm; involucre glabrous or sparsely strigose to minutely bristly; central colored part of middle phyllaries resin-filled, +- red-brown when dry"	"Erigeron canadensis"
33	"Inflorescence generally raceme-like, heads 1--12; rays 2--3 mm; involucre +- rough-hairy; central colored part of middle phyllaries not resin-filled, not red-brown when dry"	"Erigeron lonchophyllus"
34	"Annual (biennial to short-lived perennial herb) from slender taproot or shallow fibrous roots (see also <i>Erigeron philadelphicus</i> var. <i>philadelphus</i>)"	35
34	"Perennial herb or subshrub from woody taproot, branched caudex, or rhizome"	38
35	"Ray flower pappus 0; plant fibrous-rooted"	36
35	"Ray flower pappus present; plant taprooted (<i>Erigeron flagellaris</i> generally fibrous-rooted)"	37
36	"Leaves generally coarsely toothed; stem hairs sparsely spreading or appressed"	"Erigeron annuus"
36	"Leaves generally entire; stem hairs appressed"	"Erigeron strigosus var. strigosus"
37	"Stem hairs appressed; plant with herbaceous, leafy runners"	"Erigeron flagellaris"
37	"Stem hairs spreading; plant without runners"	"Erigeron divergens"
38	"Leaves 1--4-ternately dissected"	39
38	"Leaves entire to shallowly toothed"	40
39	"Leaves generally (1)2--3(4)-ternately dissected; ray < 1 mm wide; caudex branches short, thick, ascending"	"Erigeron compositus"
39	"Leaves deeply 3-lobed at tip; ray 1--2 mm wide; caudex branches thin, rhizome-like"	"Erigeron vagus"
40	"Leaf bases hardened, white-shiny, expanded, enclosing proximal stem"	41
40	"Leaf bases +- thin, not hardened, barely or not expanded"	43
41	"Caudex branches thick, leaf bases persistent; rays yellow"	"Erigeron linearis"
41	"Caudex branches slender, rhizome-like, leaf bases not persistent; rays white, pink to blue or lavender"	42
42	"Involucre 13--18 mm diam; basal leaves generally 2--5 mm wide; pappus bristles 25--40; phyllary hairs spreading; >= 2100 m; CaRH, n&c SNH"	"Erigeron barbellulatus"
42	"Involucre 6--11 mm diam; basal leaves generally 0.5--1 mm wide; pappus bristles 20--30; phyllary hairs appressed; 1000--2200 m; MP"	"Erigeron elegantulus"
43	"Fruit ribs 4--8; herbage generally +- silvery, hairs dense, appressed"	44
43	"Fruit ribs generally 2 (if more, herbage not silvery)"	46
44	"Fruit ribs 6--8; basal leaves tufted, persistent"	"Erigeron argentatus"
44	"Fruit ribs 4(6); basal leaves generally 0 at flower"	45
45	"Outer pappus conspicuous, of bristles or narrow scales; stem silvery-white"	"Erigeron parishii"
45	"Outer pappus inconspicuous; stem gray-green, densely strigose"	"Erigeron utahensis"
46	"Phyllaries strongly graduated; leaves entire, not clasping, basal 0, cauline generally evenly sized and spaced"	47
46	"Phyllaries generally +- equal; leaves entire to lobed, sometimes clasping, basal sometimes present, cauline often strongly reduced distally on stem, if present"	62
47	"Stem minutely glandular"	"Erigeron aequifolius"
47	"Stem generally not glandular"	48
48	"Stem hairs dense, minutely curled- or bent; fruit glabrous"	"Erigeron blochmaniae"
48	"Stem hairs 0 to dense, straight, stiffly spreading to +- reflexed or appressed; fruit sparsely strigose"	49
49	"Stem hairs dense, stiffly spreading, generally slightly reflexed"	50
49	"Stem hairs +- 0 or sparse, appressed"	55
50	"Herbage hairs 0.5--1 mm; phyllaries densely minutely glandular, inner phyllary tips widely white-thick-margined; stem often from woody basal offsets and roots"	"Erigeron klamathensis"
50	"Herbage hairs <= 0.1--0.4 mm; phyllaries glandular or glandless, inner phyllary tips green; stem from +- slender, rhizome-like bases"	51
51	"Phyllaries densely glandular, glandless hairs 0 or very sparse"	52
51	"Phyllaries not or barely glandular, glandless hairs prominent"	53
52	"Stem generally >= 20 cm, ascending to erect; leaves generally >= 15 mm"	"Erigeron breweri var. breweri"
52	"Stem 7--15 cm, prostrate to decumbent; leaves 5--12 mm"	"Erigeron breweri var. jacinteus"
53	"Stem 20--30 cm, wiry, brittle; phyllary hairs long, thick-based, stiffly spreading, translucent (also some glandular)"	"Erigeron breweri var. porphyreticus"
53	"Stem 30--75 cm, not wiry or brittle; phyllary hairs short, white, +- appressed, glandless"	54
54	"Phyllary hairs thin-based, +- appressed, slightly less dense on inner phyllaries"	"Erigeron breweri var. bisanctus"
54	"Phyllary hairs thick-based, ascending, much less dense on middle and inner phyllaries"	"Erigeron breweri var. covillei"
55	"Stem prostrate to +- erect, from slender rhizome"	"Erigeron elmeri"
55	"Stem decumbent to erect, from woody taproot"	56
56	"Ray flowers 9--13; leaf ciliate, hairs thin-based; phyllaries with minute glandless hairs and densely minutely glandular"	"Erigeron serpentinus"
56	"Ray flowers 15--60; leaf ciliate, hairs thick-based; phyllaries glandular or glandless"	57
57	"Phyllaries +- glandless, 0.5--0.8 mm wide, margins generally thick to +- scarious"	58
57	"Phyllaries minutely but prominently glandular, 0.8--1 mm wide, margins generally widely scarious"	60
58	"Leaves 2--4(5) cm, oriented variously; inner phyllaries 3.2--4.5 mm"	"Erigeron 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
59	"Stem 30--85 cm; axillary leaf tufts 0; leaves 35--80 mm, 1--2(4) mm wide; inner phyllaries not strongly scarious; ray flowers 26--50"	"Erigeron foliosus var. hartwegii"
59	"Stem 15--28 cm; axillary leaf tufts generally present; leaves 25--45 mm, (2)5--8 mm wide; inner phyllary margins strongly scarious; ray flowers 18--22"	"Erigeron mariposanus"
60	"Phyllary hairs all glandular; leaves generally 1--2 mm wide"	"Erigeron foliosus var. confinis"
60	"Phyllary hairs glandular and glandless, +- densely bristly-strigose; leaves generally 2--4 mm wide"	61
61	"Leaf blades +- strigose; phyllary midvein raised, orange-resinous; ray corolla 7--10 mm"	"Erigeron foliosus var. franciscensis"
61	"Leaf blades +- glabrous (except ciliate hairs); phyllary midvein generally not raised or orange-resinous; ray corolla 10--15 mm"	"Erigeron foliosus var. mendocinus"
62	"Plant fibrous-rooted, generally from obvious rhizome or +- decumbent caudex; cauline leaves often +- clasping;"	63
62	"Plant taprooted or with taprooted caudex; cauline leaves not at all clasping"	73
63	"Glandless phyllary hairs with black cross-walls (sometimes only on basal cells of hairs)"	64
63	"Glandless phyllary hairs 0 or with clear cross-walls"	65
64	"Rays white"	"Erigeron coulteri"
64	"Rays blue to purple"	"Erigeron sanctarum"
65	"Ray flowers 150--400"	"Erigeron philadelphicus var. philadelphicus"
65	"Ray flowers 20--165"	66
66	"Leaves thick, +- fleshy, entire or toothed; coastal"	"Erigeron glaucus"
66	"Leaves +- thin, entire; coastal or inland"	67
67	"Glandless phyllary hairs prominent, glandular hairs sometimes present"	68
67	"Glandless phyllary hairs 0, glandular hairs dense"	70
68	"Stem from thin, often stolon-like caudex branches with few fibrous roots"	"Erigeron sanctarum"
68	"Stem from short, thick, strongly fibrous-rooted rhizome or caudex"	69
69	"Stem 2--20(30) cm, hairs spreading; phyllaries +- black-purple; pappus bristles 12--16(20)"	"Erigeron algidus"
69	"Stem 30--100 cm, hairs appressed; phyllaries +- green; pappus bristles 20--30"	"Erigeron aliceae"
70	"Stem glabrous or sparsely minutely glandular; ray flowers 20--30(45)"	"Erigeron cervinus"
70	"Stem +- appressed-hairy, sometimes also +- bristly; ray flowers 30--105"	71
71	"Fruit 2(4)-ribbed, moderately to densely strigose; proximal leaves generally coarsely dentate, sometimes entire"	"Erigeron aliceae"
71	"Fruit 4--7-ribbed, sparsely strigose; proximal leaves entire"	72
72	"Peduncles densely minutely strigose with loosely appressed, slightly crinkled hairs"	"Erigeron glacialis var. glacialis"
72	"Peduncles bristly or +- stiffly long-soft-hairy"	"Erigeron glacialis var. hirsutus"
73	"Stem spreading- or reflexed-hairy"	74
73	"Stem glabrous or ascending- to appressed-hairy (to +- spreading-hairy in <i>Erigeron lassenianus</i>)"	79
74	"Leaf clearly petioled, blade oblanceolate, elliptic, obovate to spoon-shaped"	75
74	"Petiole indistinct, blade linear or oblanceolate, gradually tapered to base"	76
75	"Basal leaves 20--70 mm; cauline leaves much reduced; stem 2--30 cm; phyllaries +- black-purple; ray flowers (30)50--125, ray 7--13 mm"	"Erigeron algidus"
75	"Basal leaves 5--25 mm; cauline leaves 0; stem 1--4 cm; phyllaries green; ray flowers 15--40, ray 4--6 mm"	"Erigeron uncialis var. uncialis"
76	"Margins of proximal leaves generally hairy but not stiffly spreading-ciliate; generally > 2200 m"	77
76	"Margins of proximal leaves generally stiffly long-spreading-ciliate; 1200--1800 m"	78
77	"Basal leaves 20--80 mm; stem sparsely minutely glandular at least distally, and moderately hairy with short, stiffly spreading to reflexed, glandless hairs; phyllaries green; ray flowers 25--55, ray 6--11 mm"	"Erigeron clokeyi var. pinzliae"
77	"Basal leaves 6--35 mm; stem densely minutely glandular, also with short-stiff and +- spreading glandless hairs; phyllaries +- black-purple; ray flowers 20--37, ray 4--7(10) mm"	"Erigeron pygmaeus"
78	"Disk corolla (+-) glabrous; pappus bristles 12--22; outer pappus of inconspicuous bristles or narrow scales; rays (40)55--115, 8--12 mm"	"Erigeron pumilus var. intermedius"
78	"Disk corolla sharply scabrous; pappus bristles 5--15; outer pappus of prominent wide scales; rays 40--60, 7--9 mm"	"Erigeron concinnus var. concinnus"
79	"Ray flowers 75--125; disk corolla throat +- widened"	"Erigeron multiceps"
79	"Ray flowers generally 14--80; disk corolla +- narrowly cylindric"	80
80	"Basal leaves 0 at flower"	81
80	"Basal leaves generally persistent"	82
81	"Leaves sharply reduced distally on stem; axillary leaf tufts 0; ray flowers 12--27(45)"	"Erigeron oxyphyllus"
81	"Only most distal cauline leaves reduced; leaf tufts in axils; ray flowers 45--80"	"Erigeron karvinskianus"
82	"Basal leaves thread-like to linear"	83
82	"Basal leaves narrowly oblanceolate to elliptic or spoon-shaped (or linear in <i>Erigeron lassenianus</i> var. <i>lassenianus</i> and <i>Erigeron robustior</i>)"	84
83	"Stem 2--8 cm, leafless; stem hairs straight, appressed; basal leaves 5--25 mm; fruit ribs densely ciliate, faces glabrous"	"Erigeron compactus"
83	"Stem 15--30 cm, generally leafy, at least proximally; stem hairs curved up, +- loose; basal leaves generally 20--70 mm; fruit ribs and faces sparsely hairy"	"Erigeron filifolius"
84	"Plants cespitose; caudex stout, branched; basal leaves oblanceolate to elliptic, petioled; cauline leaves abruptly reduced"	"Erigeron tener"
84	"Plants not cespitose, caudex generally slender; basal leaves linear to narrowly oblanceolate, petiole indistinct; cauline leaves gradually reduced"	85
85	"Basal leaves generally persistent; cauline leaves generally smaller than basal; heads 1--4(7)"	86
85	"Basal leaves persistent at, or withering before, flower; cauline leaves gradually or little reduced; heads (1)2--7(18)"	88
86	"Involucre (14)17--23 mm diam; longest phyllaries 7--11 mm; disk corolla 4.4--6.8 mm"	"Erigeron eatonii var. nevadincola"
86	"Involucre 8--16 mm diam; longest phyllaries 5--8 mm; disk corolla 3--5 mm"	87
87	"Stem 10--23 cm; disk corolla 3--4 mm; pappus bristles 16--20, 3--3.5 mm"	"Erigeron eatonii var. plantagineus"
87	"Stem 4--12(21) cm; disk corolla 3.5--5 mm; pappus bristles 18--30, 3.5--5 mm"	"Erigeron eatonii var. sonnei"
88	"Phyllaries densely minutely glandular; involucre 4--5.5 mm, 6--10(12) mm wide; leaves generally 1-veined"	"Erigeron lassenianus var. lassenianus"
88	"Phyllaries generally glandless; involucre generally 6--8.5 mm, (9)12--20 mm wide; leaves generally 3-veined"	89
89	"Plants 10--22(27) cm; taproots +- thick, (3)5--8 mm wide; basal leaves oblanceolate to +- narrowly spoon-shaped; cauline leaves +- continuing to heads; involucres (5)6--7 mm, 9--12(14) mm wide; phyllaries elliptic-oblanceolate to oblong-oblanceolate, abruptly acuminate"	"Erigeron maniopotamicus"
89	"Plants (15)25--55 cm; taproots +- thin, 2--3 mm wide; basal leaves linear to very narrowly oblanceolate; cauline leaves ending +- well below heads; involucres 6--8.5 mm, (12)14--20 mm wide; phyllaries narrowly oblanceolate to lanceolate, acute-acuminate"	"Erigeron robustior"