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  | 1 | Plants perennials, sometimes flowering first year |  | (2) |  
  | + | Plants annuals, rarely perennials |  | (5) |  
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  | 2 (1) | Leaf blades pilose or hirsute on one or both surfaces |  | (3) |  
  | + | Leaf blades densely tomentose on one or both surfaces |  | (4) |  
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  | 3 (2) | Perianths densely hirsute; leaf blades short-hirsute on both surfaces or at least adaxially; Arizona, s and ec California, nw and sw Colorado, s Nevada, nw New Mexico, s and e Utah |  | 147 Eriogonum inflatum (in part) |  
  | + | Perianths glabrous; leaf blades sparsely pilose on both surfaces; nc and nw Arizona |  | 160 Eriogonum arizonicum |  
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  | 4 (4) | Peduncles absent or horizontal, 0.1-2 mm; leaves basal, blade densely tomentose abaxially, tomentose to floccose or glabrous adaxially; se California |  | Eriogonum cf. moranii (see discussion under subg. Ganysma1) |  
  | + | Peduncles erect to spreading, 6-60 mm; leaves basal or basal and sheathing up stems, blade densely tomentose on both surfaces; se Colorado, New Mexico, w Oklahoma, w and c Texas |  | 176 Eriogonum tenellum |  
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  | 5 (1) | Leaves basal and cauline, not basal only or basal and sheathing up stem |  | (6) |  
  | + | Leaves basal and sometimes sheathing up stem, not basal and cauline |  | (18) |  
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  | 6 (5) | Involucres glandular-puberulent or puberulent |  | (7) |  
  | + | Involucres glabrous, hispid, or villous, not puberulent or glandular-puberulent |  | (11) |  
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  | 7 (6) | Tepals monomorphic, oblong to elliptic, not inflated |  | (8) |  
  | + | Tepals dimorphic, outer ones elliptic, obovate, spatulate, or roundish, sometimes inflated apically or basally, inner ones narrowly lanceolate to spatulate |  | (9) |  
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  | 8 (7) | Involucres not densely tomentose abaxially, 1.8-2 mm; flowers 2-2.5 mm; s California |  | 197 Eriogonum gracillimum |  
  | + | Involucres densely tomentose abaxially, 2.7-3 mm; flowers 1.5-1.7 mm; sc California |  | 198 Eriogonum gossypinum |  
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  | 9 (7) | Outer tepals elliptic to obovate, not obviously inflated or, if so, only proximally; inner tepals narrowly spatulate; stamens exserted; s California |  | 194 Eriogonum angulosum |  
  | + | Outer tepals elliptic to roundish or obovate to spatulate, obviously inflated proximally or distally; inner tepals narrowly spatulate or lanceolate; stamens included; widespread w United States |  | (10) |  
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  | 10 (9) | Outer tepals inflated from base to middle; peduncles and involucres glandular-puberulent; Arizona, ec and s California, sw Idaho, Nevada, nw New Mexico, e Oregon, w Utah, se Washington |  | 195 Eriogonum maculatum |  
  | + | Outer tepals inflated above middle; peduncles and involucres glandular; s California |  | 196 Eriogonum viridescens |  
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  | 11 (6) | Perianths hirsutulous with hooked hairs; California (E. inerme introduced and disjunct in Boise County, Idaho) |  | (12) |  
  | + | Perianths glabrous or, if hairy, without hooked hairs; widespread |  | (13) |  
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  | 12 (11) | Involucres 2-flowered; achene beaks exserted; flowers 0.8-1.1 mm |  | 192 Eriogonum hirtiflorum |  
  | + | Involucres 4-6-flowered; achene beaks included; flowers 1.2-1.8 mm |  | 193 Eriogonum inerme |  
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  | 13 (11) | Basal leaves essentially glabrous on both surfaces; e Montana, sc North Dakota and w South Dakota or ne New Mexico, or if glabrous or thinly floccose then perianths densely short-villous and plants of California |  | (14) |  
  | + | Basal leaves villous to hoary-tomentose or hispid on both surfaces; Arizona, Nevada, New Mexico (not Colfax County), Utah, Texas, Idaho, Oregon, and California |  | (16) |  
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  | 14 (13) | Peduncles capillary, 0.5-2 cm; perianths densely short-villous; sw California |  | 156 Eriogonum ordii (in part) |  
  | + | Peduncles slender, absent or confined to first node, 0.3-1.5 cm; perianths sparsely hispid or glabrous; e Montana to n New Mexico |  | (15) |  
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  | 15 (14) | Perianths sparsely hispid, (1.2-)1.5-2.5 mm; involucres turbinate, 1-1.5(-2) × 0.8-1.5 mm; e Montana, sc North Dakota, w South Dakota |  | 157 Eriogonum visheri |  
  | + | Perianths glabrous, 1.2-2 mm; involucres turbinate-campanulate, 1-1.3 × 1-1.2 mm; ne (Colfax County) New Mexico |  | 158 Eriogonum aliquantum |  
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  | 16 (13) | Basal leaf blades oblong to obovate, villous to hoary-tomentose on both surfaces; tepals dimorphic, those of outer whorl orbiculate-cordate, not basally 2-saccate; Arizona, New Mexico, w Texas |  | 189 Eriogonum abertianum |  
  | + | Basal leaf blades linear-lanceolate to linear-oblanceolate and densely lanate abaxially, or linear and hispid on both surfaces; tepals dimorphic, those of outer whorl oblong-ovate and 2-saccate proximally, or monomorphic; widespread |  | (17) |  
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  | 17 (16) | Tepals dimorphic, those of outer whorl 2-saccate proximally; involucres 5-toothed; n and e Arizona, se Nevada, New Mexico, sw Utah |  | 190 Eriogonum pharnaceoides |  
  | + | Tepals monomorphic, not 2-saccate proximally; involucres 4-toothed; e California, c Idaho, w Nevada, s Oregon |  | 191 Eriogonum spergulinum |  
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  | 18 (5) | Leaf blades variously glabrous or floccose, villous, pilose, strigose, hirsute, or hispid on one or both surfaces |  | (19) |  
  | + | Leaf blades densely tomentose to floccose-tomentose or floccose on one or both surfaces |  | (35) |  
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  | 19 (18) | Perianths glabrous |  | (20) |  
  | + | Perianths pubescent |  | (25) |  
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  | 20 (19) | Peduncles 0.1-0.5 at proximal nodes; involucres sessile distally; nw Nevada |  | 165 Eriogonum lemmonii |  
  | + | Peduncles (0.05-)0.2-3(-4) cm at least on proximal nodes; involucres usually pedunculate distally or, if sessile distally, not of nw Nevada; widespread |  | (21) |  
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  | 21 (20) | Involucres narrowly turbinate to turbinate |  | (22) |  
  | + | Involucres campanulate |  | (23) |  
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  | 22 (21) | Peduncles 0.2-1.5 cm, slender to filiform, spreading to reflexed; leaf blades obovate to round-obovate; involucres 0.8-1.8 × 0.5-1.2 mm; perianths white to pinkish; flowering stems not fistulose; ec California, c and ne Nevada, c Utah |  | 162 Eriogonum esmeraldense |  
  | + | Peduncles (0.05-)0.1-0.25 cm, slender, deflexed; leaf blades subcordate; involucres 1.2-1.6 × 1-1.4 mm; perianths greenish white to reddish; flowering stems usually slightly fistulose; sc Nevada |  | 163 Eriogonum concinnum |  
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  | 23 (21) | Perianths pale yellow to yellow or yellowish red; involucres 2.5-3 × 2.5-3 mm; nw Nevada |  | 164 Eriogonum rubricaule |  
  | + | Perianths white, becoming pink to rose, rarely yellowish; involucres 0.6-1.5 × 0.8-1.5 mm; Arizona, w Colorado, nw Nebraska, nw New Mexico, sw South Dakota, Utah, and sw Wyoming |  | (24) |  
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  | 24 (23) | Tepals monomorphic, oblong to narrowly ovate, not swollen proximally; flowers 1-2.5 mm; achenes 2-2.5 mm; nc Arizona, w Colorado, nw Nebraska, sw South Dakota, e Utah, sw Wyoming, and nw New Mexico |  | 159 Eriogonum gordonii |  
  | + | Tepals dimorphic, those of outer whorl pandurate with swollen auriculate bases; flowers 1-1.6 mm; achenes 1.3-1.6 mm; se Arizona, sw New Mexico |  | 161 Eriogonum capillare |  
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  | 25 (19) | Perianths densely short-villous or puberulent, white to pink or red, rarely pale yellow or yellow |  | (26) |  
  | + | Perianths pilose or hirsute, usually yellow |  | (28) |  
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  | 26 (25) | Plants glabrous and sparsely floccose; leaf blades oblong-oblanceolate to obovate, thinly floccose or glabrous; sw California |  | 156 Eriogonum ordii (in part) |  
  | + | Plants glabrous and sparsely glandular, at least on aerial flowering stems; leaf blades oblanceolate to obovate or spatulate, sparsely pilose and glandular or hirsute; s California |  | (27) |  
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  | 27 (26) | Perianths white to reddish, rarely yellow; flowers 1.5-2.5 mm; leaf blades pilose; involucres 1.2-1.5 mm; sc California |  | 154 Eriogonum apiculatum |  
  | + | Perianths pink to red; flowers 0.5-0.9 mm; leaf blades hirsute; involucres 0.5-0.9 mm; s California |  | 155 Eriogonum parishii |  
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  | 28 (25) | Plants densely glandular throughout; perianths yellow to reddish or white to pinkish |  | (29) |  
  | + | Plants glabrous or glandular only at base of stems or occasionally at nodes; perianths yellow to greenish yellow or reddish |  | (30) |  
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  | 29 (28) | Perianths yellow to reddish; involucres 1.3-2 mm; peduncles ascending to erect; achenes 1.5-1.8 mm; s and ne Nevada, wc Utah |  | 152 Eriogonum howellianum |  
  | + | Perianths white to pinkish; involucres 0.8-1.2(-1.5) mm; peduncles deflexed or nearly so; achenes 1-1.3 mm; se California, s Nevada |  | 153 Eriogonum glandulosum |  
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  | 30 (28) | Flowering stems glandular proximally |  | (31) |  
  | + | Flowering stems glabrous, hirsute, or villous proximally |  | (32) |  
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  | 31 (30) | Inflorescence branches glandular at proximal nodes; involucral teeth (4-)5; plants (0.3-)0.5-3 dm; leaf blades oblong to round, (0.3-)0.5-1(-1.4) × (0.3-)0.5-1(-1.4) cm; achenes 1.5-1.8(-2) mm; Mojave Desert, se Inyo County, California, sw Nye County, Nevada |  | 149 Eriogonum contiguum |  
  | + | Inflorescences branches glabrous at proximal nodes; involucral teeth 4; plants (2-)4-18(-22) dm; leaf blades round to reniform, (0.5-)1-2.5(-4) × (0.5-)1-2(-3) cm; achenes 2-2.5 mm; Coast, Transverse, and Peninsular ranges and Mojave Desert of c and s California, Mojave Desert and s edge of Great Basin, s Nevada |  | 150 Eriogonum clavatum (in part) |  
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  | 32 (30) | Flowering stems and inflorescence branches grayish; plants first-year flowering perennials; e California to w Colorado and nw New Mexico |  | 147 Eriogonum inflatum (in part) |  
  | + | Flowering stems and inflorescence branches greenish or yellowish green; plants annuals; e California to sw Colorado and w Texas |  | (33) |  
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  | 33 (32) | Flowering stems villous proximally; flowers 1.3-1.6 mm; Colorado Plateau, e Utah, nw Colorado, and sw Wyoming |  | 148 Eriogonum fusiforme |  
  | + | Flowering stems minutely hirsute to short-hispid or sometimes minutely glandular proximally; flowers 1-2.5 mm; not on Colorado Plateau |  | (34) |  
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  | 34 (33) | Involucres 1-1.5(-1.8) mm; plants (2-)4-18(-22) dm; inflorescences 30-150(-170) cm; achenes 2-2.5 mm; Coast, Transverse and Peninsular ranges and Mojave Desert of c and s California, Mojave Desert and s edge of Great Basin, s Nevada |  | 150 Eriogonum clavatum (in part) |  
  | + | Involucres 0.7-1 mm; plants 1-4.5(-6) dm; inflorescences 5-30 cm; achenes 1-1.5 mm; s Mojave, Sonoran, and nw Chihuahuan deserts, Arizona, s California, s Nevada, s New Mexico, sw Utah |  | 151 Eriogonum trichopes |  
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  | 35 (18) | Outer tepals usually oblong, obovate, or orbiculate, cordate proximally |  | (36) |  
  | + | Outer tepals oblong to oblanceolate or ovate, truncate to obtuse proximally |  | (41) |  
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  | 36 (35) | Peduncles absent or erect, 0.1-5 mm |  | (37) |  
  | + | Peduncles absent or deflexed, 0.1-15 mm |  | (38) |  
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  | 37 (36) | Flowering stems 0.05-0.3 dm; plants 1-4 dm; inflorescences spreading and flat-topped; se Inyo County, California, nw Clark and sw Nye counties, Nevada |  | 170 Eriogonum bifurcatum |  
  | + | Flowering stems (0.5-)1-2 dm; plants (0.5-)3-6(-10) dm ; inflorescences narrowly erect and strict; nw Arizona, s Nevada, sw Utah, and s California |  | 171 Eriogonum exaltatum |  
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  | 38 (36) | Flowering stems and inflorescence branches glandular; s and w edge of Great Basin, Mojave and nw Sonoran deserts, nw Arizona, se and ec California, wc and s Nevada, sw Utah |  | 169 Eriogonum brachypodum |  
  | + | Flowering stems and inflorescence branches glabrous; Great Basin, Mojave and Sonoran deserts, and Colorado Plateau; Arizona, e and s California, w Colorado, se Idaho, Nevada, w New Mexico, se Oregon, sw Wyoming, and Utah |  | (39) |  
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  | 39 (38) | Involucres broadly campanulate to hemispheric; peduncles absent; perianths yellow to reddish yellow; Intermountain Region and Colorado Plateau, n Arizona, ec California, w Colorado, se Idaho, Nevada, nw New Mexico, se Oregon, sw Wyoming, and Utah. |  | 168 Eriogonum hookeri |  
  | + | Involucres narrowly turbinate or narrowly campanulate; peduncles absent or 0.1-15 mm; tepals as long or longer than wide; perianths white to pink; Arizona, s California, s Nevada, sw New Mexico, wc and s Utah |  | (40) |  
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  | 40 (39) | Involucres 1.5-2.5 mm; inflorescences variously branched, not of many horizontal tiers; Arizona, se California, s Nevada, sw New Mexico, wc and s Utah. |  | 166 Eriogonum deflexum (in part) |  
  | + | Involucres 1-1.5 mm; inflorescences of many horizontal tiers ofbranches; e Inyo County, California, and sw Nye County, Nevada |  | 167 Eriogonum rixfordii |  
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  | 41 (35) | Perianths pustulose at least proximally |  | (42) |  
  | + | Perianths not pustulose |  | (44) |  
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  | 42 (41) | Flowering stems and inflorescence branches scabrellous; e Utah, nw and sw Colorado, nw New Mexico |  | 174 Eriogonum scabrellum |  
  | + | Flowering stems and inflorescence branches glabrous, except for proximal floccose stems in some; ne California, sw Idaho, nw Nevada se Oregon |  | (43) |  
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  | 43 (42) | Peduncles curving, ascending, 1-5 cm; achenes 2-2.5 mm; ne Californianw Nevada, se Oregon |  | 187 Eriogonum collinum |  
  | + | Peduncles straight, erect, 0.1-0.5 cm; achenes 1.6-2 mm; sw Idaho, ncNevada, se Oregon |  | 188 Eriogonum salicornioides |  
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  | 44 (41) | Tepals monomorphic |  | (45) |  
  | + | Tepals dimorphic or, if monomorphic, then pandurate to flatbellate or ovate, rarely oblong and perianth glandular-pubscent |  | (49) |  
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  | 45 (44) | Involucres 1-2 mm, 5-toothed; Death Valley region, California |  | (46) |  
  | + | Involucres 0.3-1.2 mm, 4-5-toothed; n Arizona, sw Colorado, e Nevada, nw New Mexico, s Utah |  | (47) |  
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  | 46 (45) | Flowering stems and branches glabrous; peduncles erect; flowers1.5-1.8 mm |  | 172 Eriogonum hoffmannii |  
  | + | Flowering stems and branches glandular; peduncles deflexed; flowers 2-2.5 mm |  | 175 Eriogonum eremicola |  
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  | 47 (45) | Flowering stems and branches minutely viscid; perianths pale yellow to yellow, glabrous; flowers 1.3-2 mm; se Nevada, nw Arizona |  | 186 Eriogonum viscidulum |  
  | + | Flowering stems and branches glabrous or floccose to glabrescent at base of stems, not viscid; perianths white to rose, sometimes yellowish to red, glabrous or puberulent to sparsely hirsute; flowers 0.5-1.5(-2) mm; n Arizona, sw Colorado, nw New Mexico, s Utah |  | (48) |  
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  | 48 (47) | Perianths yellowish to red, becoming pink to rose; flowers 0.5-1.5 mm; involucral teeth 4; inflorescences diffuse; ne Arizona, sw Colorado, nw New Mexico, se Utah |  | 184 Eriogonum wetherillii |  
  | + | Perianths white to rose, rarely yellowish; flowers 0.6-1.6(-2) mm; involucral teeth 5; inflorescences open to somewhat diffuse; n Arizona, nw New Mexico, s Utah |  | 185 Eriogonum subreniforme |  
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  | 49 (44) | Perianths glandular |  | (50) |  
  | + | Perianths glabrous |  | (53) |  
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  | 50 (49) | Perianths white to red, glandular-puberulent, with a tuft of long white hairs adaxially; outer tepals broadly pandurate or flabellate; Arizona, s California, sw New Mexico |  | 180 Eriogonum thurberi |  
  | + | Perianths yellow or, if becoming whitish, outer tepals saccate-dilated proximally, glandular or short-hispidulous, without a tuft of long white hairs adaxially; Arizona, s California, Nevada, se Oregon, w Utah, and Mexico |  | (51) |  
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  | 51 (50) | Outer tepals cordate, becoming saccate-dilated proximally; perianths yellow in early anthesis, becoming white to rose; involucres 0.6-1.2 mm, glabrous; Arizona, se California, s Nevada, sw Utah |  | 181 Eriogonum thomasii |  
  | + | Outer tepals oblong-elliptic to obovate or ovate, not saccate-dilated proximally; perianths yellow; involucres 1-2 mm, glabrous or glandular; w Arizona, s and e California, w and s Nevada, se Oregon, w Utah |  | (52) |  
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  | 52 (51) | Involucres glandular-puberulent; nw Arizona, se California, wc and s Nevada, se Oregon, and w Utah |  | 182 Eriogonum pusillum |  
  | + | Involucres glabrous; w Arizona, s California and s Nevada s to Mexico |  | 183 Eriogonum reniforme |  
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  | 53 (49) | Involucres narrowly turbinate; sw Idaho, c Nevada, se Oregon. |  | 173 Eriogonum watsonii |  
  | + | Involucres turbinate to campanulate; widespread w United States and Canada |  | (54) |  
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  | 54 (53) | Peduncles deflexed; outer tepals oblong; ec California, Nevada |  | 166 Eriogonum deflexum (in part) |  
  | + | Peduncles cernuous, ascending, or erect; widespread w United States and Canada |  | (55) |  
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  | 55 (54) | Outer tepals oblong to oval; peduncles cernuous, usually curved, glandular or infrequently glabrous; nw Arizona, ec California, se Oregon, w and ec Utah, and Nevada |  | 179 Eriogonum nutans |  
  | + | Outer tepals pandurate or flabellate; peduncles cernuous, ascending or erect, infrequently absent, glabrous; widespread w United States and Canada |  | (56) |  
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  | 56 (55) | Outer tepals pandurate; peduncles absent or cernuous to ascending, (1-)2-25 mm; involucres 1-1.5 mm wide; widespread, sw Canada to w Nebraska, ec California, s Nevada, n Arizona, and n New Mexico |  | 177 Eriogonum cernuum |  
  | + | Outer tepals flabellate; peduncles erect, 3-15 mm; involucres 1.5-2.5 mm wide; se Arizona, New Mexico, w Texas |  | 178 Eriogonum rotundifolium |  |