1	Capitula disciform or discoid		(2)
+	Capitula radiate		(17)
2 (1)	Capitula globose to rounded or oblong; involucres patelliform or hemispheric; receptacles globose to hemispheric or obconic, often swollen, or cup- or funnel-shaped peripherally, convex centrally, rarely flat or convex (Thespis); pappus absent or coroniform, rarely of 6-13 short, coarse bristles (Thespis); herbs annual, rarely perennial		(3)
+	Capitula cup-shaped; involucres hemispheric or campanulate to turbinate or cylindric; receptacles flat or ± convex, or hemispheric-flattened or hemispheric-conic to lenticular-knobby; pappus of bristles (usually numerous, usually long); herbs perennial or annual, sometimes woody vines		(7)
3 (2)	Marginal floret corolla minutely tubular or absent; pappus of 6-13 short, coarse bristles; receptacles flat or convex; leaves unlobed.		120 Thespis
+	Marginal floret corolla with filiform tube and/or lamina present; pappus absent or coroniform; receptacles globose to hemispheric or obconic, often swollen, or cup- or funnel-shaped peripherally, convex centrally; leaves often lyrately lobed or lobed, sometimes unlobed		(4)
4 (3)	Herbs prostrate; involucres patelliform		(5)
+	Herbs erect; involucres hemispheric		(6)
5 (4)	Marginal female florets cylindric-linear, funnel-shaped, or ovoid to urceolate, 2- or 3-lobed; disk florets functionally male; synflorescences racemiform or paniculiform, rarely solitary capitula.		116 Dichrocephala
+	Marginal female florets tubular, outer 2-lobed, inner 3- or 4-lobed; disk florets bisexual; synflorescences solitary capitula or laxly corymbiform.		118 Grangea
6 (4)	Leaves pinnatifid or pinnatisect; receptacles cup-shaped or funnel-shaped peripherally (female), slightly convex centrally (disk); marginal female floret lamina none (outer) or short, narrowly funnelform (inner), 2-lobed, purple; disk florets 5-lobed; achenes oblong to ± fusiform, not ribbed.		117 Cyathocline
+	Leaves sometimes lyrate, sometimes lobed, or not lobed; receptacles convex, hemispheric or globose; ray floret lamina small, rounded, ovate or linear, white to purplish; disk florets 4-lobed; achenes narrowly obovoid, 2-ribbed.		119 Myriactis
7 (2)	Capitula discoid		(8)
+	Capitula disciform		(10)
8 (7)	Achenes obovoid; leaves eglandular (or sometimes stipitate glandular); capitula solitary at ends of branches, sometimes forming open paniculate-corymbiform synflorescences; disk floret lobes unequal.		139 Aster
+	Achenes oblong or lanceolate; leaves gland-dotted or not; capitula in dense or loose corymbiform synflorescences, rarely solitary; disk floret lobes equal		(9)
9 (8)	Involucres broadly obconic to campanulate or hemispheric, phyllaries 1-3-veined; leaves sometimes 3-veined; rhizomes robust.		125 Galatella
+	Involucres shortly cylindric or sometimes obconic, phyllary midvein ± distinct; leaves 1-veined; rhizomes slender.		126 Crinitina
10 (7)	Woody vines, climbing; achenes angled, 3-ribbed.		122 Microglossa
+	Herbs perennial or annual, climbing or erect; achenes compressed, flattened or cylindric, 2-4- or more ribbed or many veined (if 3-ribbed and angled then usually on ray only and disk achenes 2-ribbed)		(11)
11 (10)	Capitula solitary or 2-4-fascicled at ends of branches, shortly pedunculate or sessile; disk corolla lobes unequal, outer 2 longer; herbs perennial, climbing or erect.		134 Heteroplexis
+	Capitula terminal, solitary or few, or in racemiform, paniculiform, or corymbiform synflorescences, pedunculate; disk corolla lobes equal; herbs perennial or annual, erect		(12)
12 (11)	Herbs annual, eglandular, glabrous (leaf margin ciliate).		144 Symphyotrichum
+	Herbs annual or perennial, glandular (sometimes eglandular), hairy		(13)
13 (12)	Involucres urceolate or subcylindric.		141 Erigeron
+	Involucres campanulate to hemispheric-campanulate		(14)
14 (13)	Disk florets functionally male (sterile); phyllaries 2- or 3-seriate.		135 Psychrogeton
+	Disk florets bisexual (fertile); phyllaries 3- or 4-seriate		(15)
15 (14)	Phyllaries subequal; disk floret limb shortly funnelform; achenes oblanceolate, flattened.		136 Neobrachyactis
+	Phyllaries imbricate (unequal); disk floret limb funnelform; achenes oblong, compressed		(16)
16 (15)	Female florets elaminate; pappus 1-seriate; synflorescences corymbiform, sometimes glomerate, glomerate-paniculiform, or paniculiform.		121 Eschenbachia
+	Female florets laminate, lamina short, filiform; pappus ± 2-seriate, outer very short, slender; synflorescences densely compound-corymbiform (see species incertae sedis after Eschenbachia).		Conyza stricta
17 (1)	Ray floret lamina yellow, orange, red, or brownish		(18)
+	Ray floret lamina white, pink, purple, or blue		(23)
18 (17)	Small shrubs; pappus 3-seriate, outermost of 6 broad scales, inner (absent in disk florets) of flattened bristles, innermost of strongly clavate bristles; leaf blade pinnatilobed; receptacles fimbriate.		133 Formania
+	Herbs perennial, sometimes biennial or annual, or subshrubs; pappus 1-3-seriate, outer few short bristles or scales, inner series of bristles, innermost sometimes ± clavate, or only short scales; leaf blade subpinnatifid or unlobed; receptacles naked		(19)
19 (18)	Disk florets functionally male (sterile)		(20)
+	Disk florets bisexual (fertile)		(21)
20 (19)	Capitula ± large; phyllaries unequal to equal; herbage sometimes or partly long white lanate or cottony; achenes 8-10-veined; pappus bristles long barbellate.		115 Nannoglottis
+	Capitula medium-sized to small; phyllaries imbricate; herbage white tomentose to lanate, sessile to short-stipitate glandular; achenes 2-ribbed; pappus bristles barbellate.		135 Psychrogeton
21 (19)	Plants resinous; phyllaries looped or hooked; pappus of few deciduous scales or awns.		143 Grindelia
+	Plants not resinous; phyllaries ± appressed; pappus 1-3-seriate, outer few short bristles or scales, inner series of bristles		(22)
22 (21)	Capitula numerous in terminal racemiform, paniculiform, or corymbose-paniculiform synflorescences; achenes obconic to cylindric, sometimes ± compressed, 8-10-veined.		140 Solidago
+	Capitula solitary; achenes oblong, compressed, 2(-4)-veined.		141 Erigeron
23 (17)	Pappus absent (that of disk sometimes 1-seriate short scales in Aster)		(24)
+	Pappus present (rarely absent on ray achene only in Erigeron)		(27)
24 (23)	Herbs scapiform, leaves basal, sometimes rosulate		(25)
+	Herbs erect, leaves basal (often withered at anthesis) and cauline		(26)
25 (24)	Phyllaries leaflike; receptacles swollen or conic; involucres hemispheric or broadly campanulate; ray florets 1-seriate; disk florets bisexual (fertile), numerous; achenes not beaked, strigillose.		123 Bellis
+	Phyllaries membranous; receptacles flat or convex; involucres campanulate; ray florets 3- or 4-seriate; disk florets functionally male (sterile), few; achenes shortly beaked, apically glandular.		130 Lagenophora
26 (24)	Herbs biennial (winter annual); ray florets 3; disk florets few, functionally male (sterile); disk achene pappus absent; ray achenes 3-ribbed.		137 Sheareria
+	Herbs perennial; ray florets numerous; disk florets numerous, bisexual (fertile); disk achene pappus absent or 1-seriate short scales; achenes 2-5- or more ribbed.		139 Aster
27 (23)	Pappus 1-seriate, of caducous, barbellate, spiniform bristles; disk florets functionally male (sterile); achenes 3-ribbed, slightly winged.		131 Calotis
+	Pappus 1-4-seriate, of persistent (deciduous in Callistephus) barbellate bristles; disk florets bisexual (fertile); achenes 2- to many ribbed, not winged		(28)
28 (27)	Outer phyllaries large, leaflike, inner scarious; pappus 3-seriate, outermost of persistent, short scales, inner 2 of deciduous bristles.		132 Callistephus
+	Outer phyllaries leaflike (not large) or membranous, inner membranous; pappus 1-4-seriate, outermost of short setae or sometimes scales, inner of persistent (sometimes deciduous) bristles		(29)
29 (28)	Ray florets sterile; achene ribs indistinct; leaf blades often gland-dotted.		125 Galatella
+	Ray florets female, fertile; achene ribs distinct; leaf blades eglandular or sessile or stipitate glandular (not gland-dotted)		(30)
30 (29)	Subshrubs, strongly branched; leaf margins often revolute; phyllaries leathery.		127 Asterothamnus
+	Herbs perennial, biennial, or annual; leaf margins flat (rarely revolute); phyllaries membranous or leaflike		(31)
31 (30)	Pappus conspicuously elongating after anthesis; herbs annual.		124 Tripolium
+	Pappus not elongating after anthesis; herbs perennial, sometimes annual or biennial		(32)
32 (31)	Leaves basal, linear; achenes slightly veined, densely sericeous, eglandular; capitula solitary.		128 Arctogeron
+	Leaves basal and cauline (sometimes reduced, then basal not linear); achenes ribbed or veined, glabrous or sparsely to densely strigillose, glandular or eglandular; capitula in synflorescences or solitary		(33)
33 (32)	Achenes 7-10-veined; stems ascending, villous, eglandular.		142 Eurybia
+	Achenes 2-6-ribbed or -veined; stems usually erect, sometimes prostrate, glabrous or hairy, glandular or eglandular		(34)
34 (33)	Disk corollas ± zygomorphic (1 lobe deeper)		(35)
+	Disk corollas actinomorphic		(36)
35 (34)	Herbs perennial, caespitose; basal leaves numerous (persistent); receptacle shallowly alveolate, naked.		138 Rhinactinidia
+	Herbs perennial, biennial, or annual, not caespitose, or rarely shrubs; basal leaves withered by anthesis; receptacle alveolate, fimbriate.		139 Aster
36 (34)	Capitula small, numerous in dense corymbiform synflorescences; stems densely glandular; disk corolla limb shortly funnelform; achenes ovoid		129 Turczaninovia
+	Capitula small or medium-sized, solitary or few to numerous in corymbiform, racemiform, or paniculiform synflorescences; stems ± glandular or eglandular; disk corolla limb cylindric to funnelform or campanulate; achenes oblong or obovoid to oblanceoloid		(37)
37 (36)	Disk floret limb cylindric to narrowly funnelform; phyllary midvein reddish or orange.		141 Erigeron
+	Disk floret limb campanulate to funnelform; phyllary midvein not reddish or orange		(38)
38 (37)	Herbs perennial, sometimes annual, biennial, or shrubs, glandular or eglandular, glabrous or hairy; involucres hemispheric to campanulate, sometimes obconic; capitula solitary or in corymbiform, sometimes paniculiform synflorescences; achenes oblong or obovoid, compressed, 2-4(-7)-ribbed, glandular or eglandular.		139 Aster
+	Herbs perennial or annual, eglandular, glabrous (except distally in lines); involucres campanulate or cylindric; capitula in paniculiform synflorescences; achenes oblanceoloid, ± compressed, 2-6-veined, eglandular.		144 Symphyotrichum