1 "Phyllary margins ± flat, not clasping or enclosing ray ovaries" 2 1 "Phyllary margins folded, ± clasping or enclosing ray ovaries" 4 2 "Pappus 2–4 mm, of plumose bristles" "Layia {Layia hieracioides}" 2 "Pappus 0 or < 1 mm, of scales or awns" 3 3 "Leaves woolly; ray corollas thin, deciduous; receptacle center with 1–6 palea-like scales" "Eriophyllum {Eriophyllum ambiguum var. paleaceum}" 3 "Leaves scabrous; ray corollas leathery, persistent; receptacle paleate throughout, paleae awn-tipped" "Sanvitalia {Sanvitalia abertii}" 4 "Mature ray fruit compressed front-to-back, adaxial face generally ± covered by phyllary margins" 5 4 "Mature ray fruit compressed side-to-side or ± 3-angled or round in ×-section, adaxial face covered by phyllary margins or not" 9 5 "Disk flowers 1(2); annual 1–20 cm" "Hemizonella {Hemizonella minima}" 5 "Disk flowers 3–120+; annual or perennial herb 2–150 cm" 6 6 "Perennial herb, rhizomed; disk corolla white" "Holozonia {Holozonia filipes}" 6 "Annual; disk corolla yellow (sometimes aging ± red)" 7 7 "Pappus of 10 obtuse scales, 3–13 mm; fruit 10-ribbed" "Achyrachaena {Achyrachaena mollis}" 7 "Pappus 0 or of awns, bristles, or acute scales, 0.5–7 mm; fruit not ribbed" 8 8 "Ray flowers 5; disk flowers 6, staminate; pappus 0" Lagophylla 8 "Ray flowers 3–27; disk flowers 5–125, bisexual; pappus of (0)1–32 awns, bristles, or scales" Layia 9 "Disk flower style bristly-puberulent proximal to minutely notched tip" "Blepharipappus {Blepharipappus scaber}" 9 "Disk flower style glabrous proximal to tapered branches" 10 10 "Perennial herb; leaves all or mostly basal, cauline 0 or proximal, few; disk pappus of narrowly awl-shaped or ± bristle-like, ciliate-plumose scales" Raillardella 10 "Annual, leafy-stemmed perennial herb, or subshrub to shrub; disk pappus 0 or of scales, often not awl-shaped or bristle-like and ciliate-plumose" 11 11 "Distal leaves and peduncle bracts generally spine-tipped; disk flowers staminate, most or all subtended by paleae" Centromadia 11 "Distal leaves and peduncle bracts not spine-tipped; disk flowers bisexual or staminate, outermost to all subtended by paleae" 12 12 "Rays yellow, sometimes proximally ± red; ray fruit generally compressed side-to-side or ± 3-angled in ×-section, abaxially rounded, adaxially ± 2-faced, angle between adaxial faces 15–70°; peduncle bracts not tipped by pit- or tack-gland" 13 12 "Rays yellow, white, or rose; ray fruit round in ×-section or nearly so (except ± flattened adaxially) or ± 3-angled [abaxially generally ± widely 2-faced, angle between those faces generally 90+°, adaxially generally ± flattened to slightly bulging]; peduncle bracts sometimes tipped by pit- or tack-gland" 17 13 "Disk pappus 0" Madia 13 "Disk pappus of 5–21 wide to bristle-like scales" 14 14 "Perennial herb" 15 14 Annual 16 15 "Anthers yellow to ± brown; ray fruit short-beaked; involucre bell-shaped, ellipsoid, or spheric" Anisocarpus 15 "Anthers ± dark purple; ray fruit beak 0; involucre bell-shaped to hemispheric" "Kyhosia {Kyhosia bolanderi}" 16 "Anthers ± yellow to ± brown" Harmonia 16 "Anthers ± dark purple" Jensia 17 "Ray fruit ± completely enfolded by a phyllary; rays yellow, sometimes ± red at base" 18 17 "Ray fruit generally partly enfolded by a phyllary, adaxial face exposed; rays yellow, white, or rose" 19 18 "Disk pappus of fringed or plumose scales" Harmonia 18 "Disk pappus 0" "Madia {Madia anomala}" 19 "Annual; leaves ± linear, generally narrowly so; ray corolla lobed (1/4)1/3–3/4+ length, lobes often spreading; peduncle bracts generally tack-gland-tipped (except in Osmadenia, ray lobes widely spreading); disk fruit not strongly ribbed" 20 19 "Annual or subshrub to shrub; leaves linear or wider; ray corolla lobed generally 1/10–1/2 length, lobes ± parallel; peduncle bracts not tack-gland-tipped unless fruits 10-ribbed" 21 20 "Ray fruit beak 0; tack glands present" Calycadenia 20 "Ray fruit short-beaked; tack glands 0" "Osmadenia {Osmadenia tenella}" 21 "Ray generally white or yellow, often abaxially red- or purple-veined; ray fruit beak 0 or inconspicuous, straight" 22 21 "Ray yellow, not abaxially purple-veined; ray fruit beak adaxial, ascending" 23 22 "Paleae restricted to outermost disk flowers; disk flowers bisexual; ray fruit hairy" Blepharizonia 22 "Paleae throughout receptacle, subtending all disk flowers; disk flowers staminate; ray fruit glabrous" "Hemizonia {Hemizonia congesta}" 23 "Annual or subshrub to shrub; peduncle bracts not pit-gland-tipped; if annual, paleae subtending only outermost disk flowers" Deinandra 23 "Annual; peduncle bracts pit-gland-tipped; paleae throughout receptacle, subtending all or most disk flowers" Holocarpha