1	Cypselae beaked (outer sometimes beakless in Hypochaeris)		(2)
+	Cypselae beakless		(26)
2 (1)	Stems scapiform		(3)
+	Stems leafy		(10)
3 (2)	Heads usually in spiciform, paniculiform, cymiform, or corymbiform arrays (sometimes borne singly)		(4)
+	Heads borne singly		(5)
4 (3)	Leaf margins spiny; calyculi 0; phyllaries in 3–5+ series, unequal; pappi of crisped (frizzy), outer and straight, coarse, inner bristles		47 Launaea (in part), p. 272
+	Leaf margins not spiny; calyculi of 5–12 bractlets; phyllaries in 1(–2) series, equal; pappi of uniform bristles		36 Crepis (in part), p. 222
5 (3)	Pappi of outer scales and inner bristles, or of aristate scales		(6)
+	Pappi of bristles		(7)
6 (5)	Cypsela beaks relatively long or 0; pappi of outer scales and inner, plumose bristles; annuals or perennials; leaves oblanceolate to oblong		52 Leontodon (in part), p. 294
+	Cypsela beaks relatively short; pappi of lanceolate, apically notched, aristate scales, aristae smooth; annuals; leaves linear to narrowly lanceolate, grasslike		65 Uropappus (in part), p. 322
7 (5)	Receptacles paleate; corollas pink, purple, lavender, or nearly white; perennials		81 Pinaropappus, p. 374
+	Receptacles usually epaleate (if paleate, corollas yellow; some Agoseris); corollas usually yellow to orange, rarely ochroleucous, pink, pinkish, purplish, or white; annuals, biennials, or perennials		(8)
8 (7)	Calyculi of (6–)8–18(–20) bractlets in 1–3 series; phyllaries equal; perennials		37 Taraxacum, p. 239
+	Calyculi 0; phyllaries equal or unequal; annuals, biennials, or perennials		(9)
9 (8)	Leaves entire, toothed, or pinnately lobed (not spiny); heads borne singly; corollas yellow, orange, pinkish, purplish, or white; pappi of ± barbellate bristles; annuals or perennials		66 Agoseris (in part), p. 323
+	Leaves often pinnately lobed, ultimate margins dentate (spiny); heads borne singly or in spiciform or paniculiform arrays; corollas yellow to ochroleucous; pappi of crisped (frizzy), outer and straight, coarse, inner bristles; annuals or biennials		47 Launaea (in part), p. 272
10 (2)	Pappi of plumose bristles or subulate scales; annuals or biennials		(11)
+	Pappi of smooth or barbellate bristles, or of subulate scales or awns, or of aristate scales; annuals, biennials, or perennials		(13)
11 (10)	Corollas white, sometimes abaxially rose- or purple-veined; calyculi of spreading to reflexed, unequal bractlets; annuals		70 Rafinesquia, p. 348
+	Corollas yellow, orange, purple, or pinkish to purplish; calyculi 0; annuals or biennials		(12)
12 (11)	Leaves linear to lance-linear or lance-attenuate, entire; peduncles inflated distally; involucres campanulate; pappi of subulate scales; biennials (winter annuals); heads borne singly; corollas yellow or purple		59 Tragopogon, p. 303
+	Leaves mostly obovate to oblong-obovate, the distal ovate to linear, usually pinnately lobed, sometimes dentate or entire; peduncles little, if at all, inflated distally; involucres urceolate; pappi of bristles; annuals; heads borne singly or in corymbiform arrays; corollas yellow, sometimes abaxially striped with red.		53 Urospermum, p. 296
13 (10)	Perennials		(14)
+	Annuals or biennials		(18)
14 (13)	Involucres narrowly cylindric, 1–2+ mm diam.; phyllaries (4–)5; florets 5; cypselae obovoid to lanceoloid		43 Mycelis (in part), p. 257
+	Involucres cylindric to campanulate, 2–5 mm diam.; phyllaries 5–21; florets 6–150+; cypselae cylindric to fusiform or lanceoloid		(15)
15 (14)	Corollas usually bluish; cypselae lanceoloid		44 Mulgedium (in part), p. 258
+	Corollas yellow to white; cypselae cylindric to fusiform		(16)
16 (15)	Phyllaries 8–21+; pappi: outer crowns of spreading, white hairs plus 2–3+ inner series of rufous to stramineous bristles		82 Pyrrhopappus, p. 376
+	Phyllaries 5–10; pappi of white bristles		(17)
17 (16)	Calyculi of 3–4, minute bractlets; involucres cylindric; cypselae cylindric, 5+-ribbed (without rings of scales); pappi of 40–50+ bristles		38 Chondrilla, p. 252
+	Calyculi of 3–10+, deltate to lanceolate bractlets; involucres campanulate to cylindric; cypselae fusiform, 10-ribbed or -winged (with rings of scales at bases of beaks); pappi of 20–30 bristles		39 Ixeris, p. 254
18 (13)	Peduncles inflated distally (fistulose); pappi of aristate scales		65 Uropappus (in part), p. 322
+	Peduncles not inflated distally; pappi of bristles or subulate scales (not aristate)		(19)
19 (18)	Receptacles paleate; outer cypselae beakless; all or inner pappus bristles plumose.		54 Hypochaeris, p. 297
+	Receptacles epaleate; all cypselae beaked; pappus bristles usually barbellulate or smooth (sometimes plumose in Helminthotheca)		(20)
20 (19)	Calyculi 0; leaves spiny		47 Launaea (in part), p. 272
+	Calyculi of 2–16 bractlets; leaves not spiny		(21)
21 (20)	Cypselae dimorphic, outer gibbous, inner ellipsoid to fusiform, not ribbed (rugulose); pappi of subulate to setiform scales		55 Helminthotheca, p. 300
+	Cypselae monomorphic, ellipsoid, oblong, obovoid, or lanceoloid, or cylindric to fusiform, ribbed; pappi of bristles (sometimes with minute outer crowns as well)		(22)
22 (21)	Cypselae ellipsoid to oblong or obovoid to lanceoloid; pappi of minute outer crowns plus inner bristles (sometimes 2–3+ series of bristles in Lactuca)		(23)
+	Cypselae fusiform, not or little compressed; pappi of bristles		(24)
23 (22)	Involucres narrowly cylindric, 1–2+ mm diam.; calyculi of 2–4 bractlets in 1 series		43 Mycelis (in part), p. 257
+	Involucres campanulate to cylindric, 2–5 mm diam.; calyculi of 3– 10+ bractlets in 2–3 series		45 Lactuca, p. 259
24 (22)	Stems dotted with tack-glands; pappus bristles basally connate (fall- ing in rings), white		61 Calycoseris, p. 307
+	Stems eglandular or glandular (without tack-glands); pappus bristles distinct or inner basally connate, white to tawny		(25)
25 (24)	Heads usually in cymiform, corymbiform, or paniculiform arrays, sometimes borne singly; corollas usually yellow or orange, sometimes white, pink, or reddish; cypselae 10–20- ribbed		36 Crepis (in part), p. 222
+	Heads borne singly; corollas white to pale yellow; cypselae 4– 5-angled or -ribbed (angles roughened)		75 Glyptopleura, p. 361
26 (1)	Stems scapiform		(27)
+	Stems leafy		(42)
27 (26)	Pappi 0 or coroniform		(28)
+	Pappi of bristles and/or scales, or of aristate scales		(31)
28 (27)	Perennials; leaves (± fleshy) linear to oblanceolate, margins entire; calyculi 0.		80 Phalacroseris, p. 374
+	Annuals or biennials; leaves obovate or oblanceolate to spatulate, margins ± dentate or lobed; calyculi of 1–10+ bractlets or 0		(29)
29 (28)	Leaf margins pinnately lobed; cypselae oblong, 10–13-ribbed		40 Lapsanastrum, p. 254
+	Leaf margins ± dentate to toothed; cypselae obovoid or subcylindric to weakly clavate, 4–5- or 8–10-ribbed		(30)
30 (29)	Leaves oblanceolate to spatulate; heads borne singly or 2–3; peduncles naked, inflated distally; involucres broadly campanulate to urceolate; phyllaries basally connate; cypselae obovoid, 8–10-ribbed		49 Arnoseris, p. 276
+	Leaves obovate; heads in corymbiform arrays; peduncles sometimes bracteate, not inflated distally; involucres cylindro-campanulate; phyllaries distinct; cypselae subcylindric or weakly clavate, 4–5-ribbed (ribs corky)		62 Atrichoseris, p. 309
31 (27)	Heads usually in corymbiform, paniculiform, or cymiform arrays; calyculi of 3–12 bractlets		(32)
+	Heads usually borne singly (sometimes in spiciform or paniculiform arrays in Launaea); calyculi 0		(33)
32 (31)	Leaves entire or dentate to pinnatifid (often lyrate or runcinate); cypselae 10– 20-ribbed; pappi of usually distinct, white to tawny bristles		36 Crepis (in part), p. 222
+	Leaves pinnately lobed (lyrate); cypselae 11–13-ribbed (ribs spiculate); pappi of basally connate, white bristles		41 Youngia, p. 255
33 (31)	Pappi of subulate or aristate scales		(34)
+	Pappi wholly or partly of bristles (in Leontodon, pappi of outer cypselae of scales, of inner cypselae of bristles; sometimes scales + bristles in Krigia)		(36)
34 (33)	Heads erect; cypselae narrowed distally; pappi of lustrous, white subulate or aristate scales (bodies narrowly lanceolate to subulate)		67 Nothocalaïs (in part), p. 335
+	Heads nodding (at least in bud); cypsela apices truncate; pappus scales silvery to yellowish, brownish, or blackish (rarely white), plumose, barbellate, or barbellulate		(35)
35 (34)	Involucres fusiform to ovoid or globose; pappi of deltate, lanceolate, linear, oblong, orbiculate, or ovate aristate scales, aristae plumose, barbellate, or barbellulate		68 Microseris (in part), p. 338
+	Involucres campanulate; pappi of narrowly lanceolate aristate scales, aristae barbellulate		69 Stebbinsoseris (in part), p. 346
36 (33)	Pappi of outer cypselae of scales, of inner cypselae of plumose bristles		52 Leontodon (in part), p. 294
+	Pappi of bristles or of outer scales plus inner bristles		(37)
37 (36)	Phyllary margins papery (wider than midribs); receptacles paleate; pappus bristles plumose		63 Anisocoma, p. 309
+	Phyllary margins not papery; receptacles usually epaleate (sometimes paleate in Agoseris); pappus bristles mostly smooth, barbellulate, or ± barbellate		(38)
38 (37)	Leaves spiny; corollas yellow to ochroleucous; pappi of crisped (frizzy), outer and coarse, straight, inner bristles		47 Launaea (in part), p. 272
+	Leaves not spiny; corollas usually yellow to orange, sometimes pink, purple, or red; pappi of ± barbellate bristles		(39)
39 (38)	Phyllaries in 1–2 series; cypselae 10–20-nerved or -ribbed; pappi of 5 outer scales plus 5–45 inner bristles		76 Krigia (in part), p. 362
+	Phyllaries in 2–5(–7) series; cypselae 8–10(–15)-ribbed; pappi of bristles in 1–6 series		(40)
40 (39)	Phyllaries hairy or glabrous; cypselae usually beaked (6– 31 mm)		66 Agoseris (in part), p. 323
+	Phyllaries usually glabrous; cypselae not beaked (5–10 mm)		(41)
41 (40)	Plants taprooted; pappi of 30–80, whitish bristles		67 Nothocalaïs (in part), p. 335
+	Plants rhizomatous (usually in bogs); pappi of 24–48, brownish bristles		68 Microseris (in part), p. 338
42 (26)	Pappi 0, or of scales or aristate scales, or of awns plus bristles, or coroniform		(43)
+	Pappi wholly or mostly of bristles (sometimes with minute outer scales)		(54)
43 (42)	Pappi 0		(44)
+	Pappi of scales or aristate scales, or of awns or subulate scales plus bristles, or coroniform		(47)
44 (43)	Stems winged, wings spiny; receptacles paleate		34 Scolymus (in part), p. 220
+	Stems not winged; receptacles epaleate		(45)
45 (44)	Heads borne singly; florets 5–35; cypselae ± monomorphic (1.3–1.7 mm).		76 Krigia (in part), p. 362
+	Heads in corymbiform or thyrsiform arrays; florets 5–15; cypselae heteromorphic (3–25 mm, outer longer than inner)		(46)
46 (45)	Leaves ovate to suborbiculate, coarsely dentate; heads in corymbiform to thyrsiform arrays; cypselae subcylindric (curved), terete to slightly compressed, ± 20-ribbed		42 Lapsana, p. 257
+	Leaves ovate-lanceolate to linear, entire or dentate to pinnately lobed; heads in ± corymbiform arrays; cypselae ± terete (outer straight or arcuate, inner straight to coiled), not ribbed		56 Rhagadiolus, p. 300
47 (43)	Corollas usually blue, sometimes pink or white; cypselae prismatic, 3–5-angled; pappi coroniform (erose scales)		35 Cichorium, p. 221
+	Corollas orange or yellow to white or pink to lavender; cypselae columnar or cylindric to fusiform or obconic, 6–15-ribbed; pappi usually of scales (scales sometimes aristate), sometimes of awns or subulate scales plus bristles, or coroniform (Krigia wrightii, annuals, cypselae 1.3–1.6 mm)		(48)
48 (47)	Phyllaries enfolding outer cypselae		(49)
+	Phyllaries not enfolding outer cypselae		(50)
49 (48)	Peduncles inflated distally; calyculi of 3–10+, deltate to lanceolate bractlets; phyllaries 5–13+ in 1 series; florets 8–30+; cypselae cylindric to fusiform, 12–15-ribbed; pappi of outer cypselae coroniform (short scales), of inner cypselae of lance-aristate to subulate-aristate scales (0–5+ outer and 5+ inner)		57 Hedypnois, p. 302
+	Peduncles not inflated distally; calyculi of 8–13, linear to filiform bractlets; phyllaries 20–25+ in 2+ series; florets 30–100+; cypselae columnar, 6–8(–10)-ribbed; pappi of setiform scales plus smooth or barbellate bristles		50 Tolpis, p. 277
50 (48)	Heads ± nodding (at least in bud); pappi of aristate scales		(51)
+	Heads erect; pappi of setiform, subulate, or aristate scales or of awns or subulate scales plus bristles		(52)
51 (50)	Perennials; involucres campanulate, fusiform, ovoid, or globose; pappus scales deltate, lanceolate, linear, oblong, orbiculate, or ovate, aristae plumose, barbellate, or barbellulate		68 Microseris (in part), p. 338
+	Annuals; involucres campanulate; pappus scales narrowly lanceolate, aristae barbellulate		69 Stebbinsoseris (in part), p. 346
52 (50)	Perennials; leaves linear to linear-lanceolate, entire; corollas pale lavender to white; cypselae 5-angled or -ridged; pappi of awns or subulate scales plus bristles		77 Chaetadelpha, p. 368
+	Annuals, biennials, or perennials; leaves ovate-lanceolate or oblong to lanceolate or linear, entire or pinnately lobed; corollas white, yellow, or purplish; cypselae sometimes 10-nerved; pappi of setiform, subulate, or aristate scales		(53)
53 (52)	Leaves oblong or lanceolate to oblanceolate or linear, spiny; involucres campanulate to urceolate; receptacles paleate; corollas yellow; cypselae obovoid, ribs 0; pappi (0 or) of 2–4 setiform to aristate scales plus 0–4 muticous to lanceolate scales.		34 Scolymus (in part), p. 220
+	Leaves ovate-lanceolate to lanceolate or linear, not spiny; involucres ovoid to cylindric; receptacles epaleate; corollas whitish to yellow or purplish; cypselae columnar to obclavate or fusiform, not compressed, usually 10-nerved; pappi of 28–50+ plumose to barbellate, subulate to setiform scales		60 Scorzonera, p. 306
54 (42)	Shrubs; California		71 Munzothamnus, p. 349
+	Annuals, biennials, or perennials		(55)
55 (54)	Corollas yellow, orange, ochroleucous, pinkish to reddish, or white (sometimes abaxially pinkish, reddish, or purplish)		(56)
+	Corollas usually purple, lavender, pink, or blue, sometimes white, rarely yellow		(62)
56 (55)	Leaves spiny (on margins, bases often auriculate); phyllaries in 3–5+ series		(57)
+	Leaves not spiny (bases not auriculate); phyllaries in 1–2+, or 2–3, or 4–6 series		(58)
57 (56)	Involucres 3–5 mm diam.; phyllaries 18–25; cypselae weakly compressed, cylindric to prismatic or fusiform, 4–5-ribbed (or grooved), ribs muricate; pappi of crisped (frizzy, often basally coherent or connate), outer plus straight, coarse, inner bristles		47 Launaea (in part), p. 272
+	Involucres 5–15+ mm diam.; phyllaries 27–50; cypselae compressed, oblong or oblanceoloid to elliptic, 2–4(–5)-ribbed, smooth, rugose, or tuberculate; pappi of distinct outer bristles plus basally coherent or connate inner bristles		48 Sonchus, p. 273
58 (56)	Calyculi 0		(59)
+	Calyculi usually of 3–16+ bractlets (sometimes intergrading with phyllaries)		(60)
59 (58)	Heads borne singly; corollas yellow to orange; pappi (usually 2-seriate): outer of 5+ scales, inner of 5–45 bristles		76 Krigia (in part), p. 362
+	Heads in corymbiform to paniculiform arrays; corollas yellow to white; pappi (1 or 2-seriate): outer pappi 0, or of minute teeth plus 0–6 bristles, inner (or only) pappi of 15–35, basally coherent bristles		64 Malacothrix, p. 310
60 (58)	Perennials; phyllaries in 2+ series; cypselae columnar or prismatic to ± urceolate		51 Hieracium, p. 278
+	Annuals, biennials, or perennials; phyllaries in 1–2 series; cypselae subcylindric to fusiform		(61)
61 (60)	Corollas yellow or orange (white, pink, reddish), not abaxially reddish; cypselae 10–20-ribbed, sometimes spiculate; pappi persistent, of distinct bristles		36 Crepis (in part), p. 222
+	Corollas yellow, often abaxially reddish; cypselae 5–10-ribbed, transversely rugulose; pappi falling, of basally connate bristles		58 Picris, p. 302
62 (55)	Annuals		(63)
+	Perennials		(65)
63 (62)	Pappus bristles distinct, plumose (at least distally)		72 Stephanomeria (in part), p. 350
+	Pappus bristles basally connate, smooth or barbellulate		(64)
64 (63)	Stems glandular-puberulent to glabrescent; leaves basal and cauline, blades spatulate to oblanceolate or minute, margins irregularly dentate to runcinate, often spinulose; peduncles minutely bracteate; cypselae columnar (tapering slightly proximally), 5-ribbed		73 Prenanthella, p. 359
+	Stems glabrous; leaves cauline (opposite proximally), blades linear, margins entire; peduncles ebracteate; cypselae subcylindric (apices abruptly constricted), 10-ribbed		78 Shinnersoseris, p. 368
65 (62)	Heads (usually nodding) in racemiform, thyrsiform, corymbiform, or paniculiform arrays; corollas usually white to pink or lavender, rarely yellow		46 Prenanthes, p. 264
+	Heads (erect) usually borne singly (sometimes in ± corymbiform to paniculiform arrays); corollas usually bluish, pink to lavender, or rose, rarely white		(66)
66 (65)	Leaves oblong, elliptic, or ovate to lanceolate or linear; phyllaries 8–13+ in 1–2 series; florets (1–)15–50+; cypselae compressed, lanceoloid		44 Mulgedium (in part), p. 258
+	Leaves linear to oblong (distal sometimes bractlike or subulate distally); phyllaries 3–10 in ± 1 series; florets 3–16; cypselae not compressed, columnar		(67)
67 (66)	Stems rigid, spine-tipped (thorny); leaves cauline, entire; phyllaries 3–5; florets 3–5		74 Pleiacanthus, p. 361
+	Stems not spine-tipped; leaves basal and cauline, entire, dentate, or pinnately lobed; phyllaries 4–10; florets (4–)5–16		(68)
68 (67)	Cypselae subcylindric, subterete, angled, or sulcate; pappus bristles barbellate		79 Lygodesmia, p. 369
+	Cypselae columnar, 5-angled; pappus bristles (wholly or partly) plumose		72 Stephanomeria (in part), p. 350