1 "Leaves and phyllaries dotted or streaked with embedded, translucent oil glands, otherwise glabrous; plant strongly pungent-scented" Porophyllum 1 "Leaves and phyllaries without embedded, translucent oil glands (sometimes stalked- or sessile-glandular, or resin-gland-dotted); plant scented or not" 2 2 "Shrub or subshrub (if perennial herb, pappus of 1--2 bristles + crown of scales)" 3 2 Herb 29 3 "Corolla white or cream to dull purple or +- green" 4 3 "Corolla yellow to orange" 9 4 "Ovaries very reduced, sterile; style included" Baccharis 4 "Ovaries forming fruits; style often exserted" 5 5 "Fruit 10-ribbed" Brickellia 5 "Fruit 5-ribbed" 6 6 "Leaf sessile, narrowly linear, entire" "Ericameria albida" 6 "Leaf sessile or petioled, blade diamond-shaped to lanceolate, elliptic, ovate or triangular, generally toothed" 7 7 "Petiole >> leaf blade; pappus of bristles and short scales" "Pleurocoronis {Pleurocoronis pluriseta}" 7 "Petiole 0 or generally <= blade; pappus of bristles only" 8 8 "Perennial herb or subshrub; leaves serrate, opposite throughout or distal alternate" Ageratina 8 "Shrub --- rigidly branched; leaves spiny-toothed, alternate throughout" "Hazardia brickellioides" 9 "Pappus bristles 1--2" 10 9 "Pappus bristles 18--many" 11 10 "Leaf blade 3--12 cm, petiole 1.5--5 cm; phyllaries in 1 series, weakly fused" "Pericome {Pericome caudata}" 10 "Leaf blade generally < 2.5 cm, petiole <= 0.6 cm; phyllaries in 2--3 equal series, free" Perityle 11 "Involucre hemispheric to +- spheric; phyllaries elliptic or widely ovate" "Acamptopappus sphaerocephalus" 11 "Involucre generally cylindric to bell-shaped or obconic (hemispheric); phyllaries linear to narrowly ovate" 12 12 "Phyllaries in 1--2 series, +- equal" 13 12 "Phyllaries graduated in several series, unequal" 14 13 "Phyllaries 9--18; plant glabrous, resinous-glandular; flowers 12--21" "Peucephyllum {Peucephyllum schottii}" 13 "Phyllaries 4--6; plant +- woolly; flowers 4--8" Tetradymia 14 "Leaves (at least distal) scale-like" 15 14 "Leaves linear to oblong, (ob)ovate, or +- round" 16 15 "Heads in panicle-like clusters; fruit +- glabrous" "Lepidospartum squamatum" 15 "Heads solitary; fruit appressed-hairy" "Leucosyris carnosa" 16 "Leaves toothed" 17 16 "Leaves entire" 18 17 "Corolla throat expanded gradually above tube" Hazardia 17 "Corolla throat expanded abruptly above tube" Isocoma 18 "Phyllaries in 5 +- distinct vertical ranks" 19 18 "Phyllaries not in distinct vertical ranks" 21 19 "Young stem densely tomentose, hairs often tightly matted" Ericameria 19 "Young stem glabrous or puberulent" 20 20 "Leaves glandless or glands, if present, not in deep, round pits" Chrysothamnus 20 "Leaves gland-dotted, glands in deep, round pits" Ericameria 21 "Stem +- tomentose" 22 21 "Stem glabrous or +- hairy but not tomentose" 25 22 "Phyllary tips thin, papery, ascending to +- spreading, creamy white; corolla +- 2.5 mm" "Helichrysum {Helichrysum petiolare}" 22 "Phyllary margins thick, generally appressed or stiffly ascending, generally green; corolla 5--12.5 mm" 23 23 "Phyllaries acuminate" Ericameria 23 "Phyllaries obtuse to acute" 24 24 "Stem loosely tomentose; pappus 3--5 mm" "Isocoma menziesii" 24 "Stem closely tomentose except glabrous ribs; pappus 8--11 mm" "Lepidospartum latisquamum" 25 "Corolla throat expanded abruptly above tube" Isocoma 25 "Corolla throat expanded gradually above tube" 26 26 "Leaves gland-dotted in deep, round pits" Ericameria 26 "Leaves glandless or glands, if present, not in deep, round pits" 27 27 "Involucre 5--10 mm" Chrysothamnus 27 "Involucre 10--17.5 mm" 28 28 "Leaves 30--85 mm, +- lanceolate; fruit glabrous; s W&I, n DMtns" "Cuniculotinus {Cuniculotinus gramineus}" 28 "Leaves 5--15 mm, linear; fruit appressed-hairy; s KR, n NCoRH" "Ericameria ophitidis" 29 "Corollas white to maroon or purple" 30 29 "Corollas yellow to orange or red" 41 30 "Leaves and phyllaries spiny" Onopordum 30 "Leaves and phyllaries not spiny" 31 31 "Pappus bristles 2--6" 32 31 "Pappus bristles generally >> 6" 34 32 "Leaves oblong to ovate, toothed; involucre widely bell-shaped to hemispheric; wet places, GV, SCo" "Trichocoronis {Trichocoronis wrightii var. wrightii}" 32 "Leaves linear, generally entire; involucre cylindric to narrowly bell-shaped" 33 33 "Corolla 5--6 mm; DSon" "Malperia {Malperia tenuis}" 33 "Corolla 2--3 mm; NCoR, SNF, GV, CW" "Pentachaeta exilis subsp. exilis" 34 "Phyllaries +- equal, in 1--2 series" 35 34 "Phyllaries unequal, graduated in several series" 37 35 "Flowers 2(3); annual; pappus bristles plumose" "Dimeresia {Dimeresia howellii}" 35 "Flowers 10--many; perennial herb; pappus bristles minutely barbed" 36 36 "Abaxial leaf face glabrous or glandular to short-bristly" Ageratina 36 "Abaxial leaf face white-tomentose" "Luina {Luina hypoleuca}" 37 "Annual; outer corollas often bilateral, +- ray-like" Lessingia 37 "Perennial herb; corollas all radial" 38 38 "Herbage glabrous, sticky" "Baccharis glutinosa" 38 "Herbage puberulent to tomentose" 39 39 "Leaves entire; involucre 3--9 mm; flowers unisexual --- plants dioecious" Antennaria 39 "Leaves sharply toothed; involucre 10--15 mm; flowers bisexual" 40 40 "Corollas cream, lobes +- deltate; style branches long, club-shaped" Brickellia 40 "Corollas white to generally +- purple, lobes linear; style branches short, oblong" "Saussurea {Saussurea americana}" 41 "Phyllaries in 2--several series, unequal, often strongly graduated" 42 41 "Phyllaries in 1--2 series, +- equal" 53 42 "Phyllaries thin-membranous, white to pink or red" 43 42 "Phyllaries not thin-membranous, not white" 44 43 "Stem from rhizome; leaf rosette withered at flower; cauline leaves long, all except distal-most +- equal" "Anaphalis {Anaphalis margaritacea}" 43 "Stem from persistent leaf rosette or thick, often branched caudex; cauline leaves generally +- reduced, at least distal-most short, 1--3 cm" Antennaria 44 "Plant low, mounded, densely gray-woolly, strongly scented; leaves often wider than long; phyllaries in 2 series, outer phyllaries wide, tips spreading" Psathyrotes 44 "Plant spreading to erect, generally not densely woolly, scented or not; leaves generally longer than wide; phyllaries in 3--several series" 45 45 "Pappus bristles flat, readily deciduous; involucre gummy" Grindelia 45 "Pappus bristles +- cylindric, +- persistent; involucre generally not gummy" 46 46 Annual 47 46 "Perennial herb --- outer-flower corollas radial, not enlarged" 49 47 "Outer-flower corollas +- bilateral, often enlarged, +- ray-like" Lessingia 47 "Outer-flower corollas radial" 48 48 "Plant 10--50 cm; phyllaries generally in 3--5 series" "Dieteria canescens var. shastensis" 48 "Plant 2--6 cm; phyllaries in 2--3 series" "Pentachaeta exilis" 49 "Phyllary tips spreading" 50 49 "Phyllary tips generally appressed (lowest sometimes spreading)" 51 50 "Leaves lanceolate to triangular; corollas creamy yellow" "Brickellia grandiflora" 50 "Leaves linear to +- obovate; corollas bright yellow" "Dieteria canescens var. shastensis" 51 "Leaves linear to narrowly oblong; disk wide, button-like" Erigeron 51 "Leaves linear to ovate; disk +- narrow" 52 52 "Hairs smooth; various habitats" Eucephalus 52 "Hairs minutely knobby (at 20×); generally dry streambanks, gravel bars" "Heterotheca oregona" 53 "Pappus bristles +- plumose" 54 53 "Pappus bristles smooth or barbed" 57 54 "Leaves all or mostly basal" Raillardella 54 "Some or all leaves cauline" 55 55 "Phyllaries in 2 series; pappus bristles +- plumose" Arnica 55 "Phyllaries or phyllary-like paleae in 1 series; pappus bristles plumose" 56 56 "Glandless hairs restricted to margins of phyllary-like paleae" "Anisocarpus scabridus" 56 "Glandless hairs not restricted to margins of phyllary-like paleae" "Carlquistia {Carlquistia muirii}" 57 "Cauline leaves opposite (distal-most sometimes alternate)" 58 57 "Cauline leaves alternate" 59 58 "Pappus bristles many; phyllaries in 2 series, free" Arnica 58 "Pappus bristles 1--2; phyllaries in 1 series, fused at base" "Pericome {Pericome caudata}" 59 "Annual or short-lived perennial herb with slender taproot" 60 59 "Perennial herb, often with caudex or rhizome" 63 60 "Main phyllaries in 1 series, outer, if present, << inner" Senecio 60 "Main phyllaries in 1--2 series, +- equal" 61 61 "Leaf thread-like to linear" "Pentachaeta exilis subsp. exilis" 61 "Leaf oblanceolate to ovate or wider" 62 62 "Pappus bristles +- free; heads short-peduncled; leaves entire or blunt-toothed" Psathyrotes 62 "Pappus bristles fused at base in 5 groups; heads long-peduncled; leaves sharply toothed or lobed" "Trichoptilium {Trichoptilium incisum}" 63 "Leaves palmately veined and lobed" 64 63 "Leaves pinnately veined (or lateral veins obscure), entire to pinnately lobed" 65 64 "Plant +- erect" "Cacaliopsis {Cacaliopsis nardosmia}" 64 "Plant a twining vine" "Delairea {Delairea odorata}" 65 "Pappus double, outer pappus of minute bristles or scales" Erigeron 65 "Pappus single (double, bristles +- equal)" 66 66 "Distal leaf blades 1.5--4 cm; phyllary tips green or red" Packera 66 "Distal leaf blades 6--25 cm; phyllary tips black or green" Senecio