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Habit Shrubs, subshrubs, or herbs, sometimes nearly arborescent, perennial, glabrous or pubescent, rarely glandular; taproot woody.
Stems

matted to spreading, decumbent, or erect, infrequently absent, with or without persistent leaf bases, glabrous or variously pubescent or glandular;

caudex stems woody, tightly compact to spreading and at or just below surface, or spreading to erect and above surface;

aerial flowering stems arising at nodes of caudex branches, at distal nodes of aerial branches, or directly from root, prostrate or decumbent to erect, slender to stout and usually solid, infrequently slightly to distinctly fistulose and hollow.

Leaves

basal, sometimes in rosettes, sometimes sheathing up stems, cauline, or basal and cauline, 1 per node or fasciculate on flowering stems, at tips of dwarf branches, or on exposed woody caudices, usually persistent, occasionally persistent through growing season or longer, rarely quickly deciduous;

blade glabrous or floccose to tomentose, occasionally also glandular.

Inflorescences

cymose, cymose-umbellate, umbellate, virgate, or racemose, mostly spreading and open to diffuse, sometimes dense, congested, or compact, sometimes reduced and in subumbellate, subcapitate, or capitate heads or reduced to a single terminal involucre;

branches open to diffuse, spreading to erect, usually dichotomously branched except for initial trichotomous node, round and smooth, rarely grooved, angled, or ridged, tomentose to floccose or glabrous, occasionally lanate or glandular, rarely scabrellous;

bracts usually 3, connate basally, usually scalelike, sometimes semileaflike or leaflike.

Peduncles

absent or erect, usually stout.

Involucres

1–8 or more per cluster, narrowly turbinate to campanulate;

teeth (3–)5–6(–10), erect or occasionally spreading, apex acute to obtuse or rounded.

Flowers

bisexual or, infrequently, unisexual, not attenuate at base, without stipelike base (except for slightly winged stipelike bases in E. saxatile and E. crocatum);

perianth various shades of white, yellow, pink, or red, glabrous, glandular, or variously pubescent abaxially, usually glabrous adaxially except for minute glands and a few scattered hairs;

tepals connate only basally or in proximal 1/2, monomorphic or dimorphic;

stamens usually exserted, sometimes included;

filaments variously pubescent but usually pilose proximally, infrequently glabrous.

Achenes

light to dark brown, not winged (but nearly so in E. saxatile), 3-gonous, glabrous, occasionally with minutely papillate beak.

Seeds

embryo curved.

Eriogonum subg. Eucycla

Distribution
w North America (including nw Mexico); mainly arid regions
Discussion

Species 107 (101 in the flora).

Species of subg. Eucycla not accounted for in this treatment are: Eriogonum encelioides Reveal & C. A. Hanson, E. fastigiatum Parry, E. molle Greene, E. orcuttianum S. Watson, E. pondii Greene, and E. zapatoense Moran. All are native to Baja California, Mexico.

The keys to species for subg. Eucycla are broken into geographic regions to aid in identification. They are: California (key 1, p. 225); British Columbia, Idaho, Oregon, and Washington (key 2, p. 228); Nevada and Utah (key 3, p. 231); Arizona and New Mexico (key 4, p. 237); Alberta, Colorado, Montana, and Wyoming (key 5, p. 239); and Manitoba, Saskatchewan, Great Plains states, and Texas (key 6, p. 242).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Key

Key 1—California

1. Flowers with winged stipelike bases
→ 2
1. Flowers without stipelike bases
→ 3
2. Perianths white to rose or yellowish; inflorescences cymose, 10-25 × 5-12 cm; achenes 3.5-4 mm; s Coast Ranges, Transverse Ranges, s Sierra Nevada, desert ranges to east
E. saxatile
2. Perianths bright yellow; inflorescences cymose-umbellate, 0.5-3 × 3-8 cm; achenes 2.5-3 mm; Santa Monica Mountains, Ventura County
E. crocatum
3. Plants forming cespitose or pulvinate mats; inflorescences capitate, or if racemose, subumbellate, cymose, or cymose-umbellate, then plants 0.1-1 dm
→ 4
3. Plants shrubs to subshrubs or spreading to erect perennials, not cespitose or matted; inflorescences branched or, if capitate, plants 1-5 dm
→ 13
4. Inflorescences cymose, racemose, subumbellate, cymose-umbellate, or virgate, not capitate
→ 5
4. Inflorescences capitate, rarely umbellate
→ 7
5. Perianths glandular-hairy, whitish to reddish; flowering stems glandular-puberulent; Kern and Tulare counties
E. breedlovei
5. Perianths glabrous, white to pink or rose, or yellowish with reddish spot; flowering stems not glandular; Inyo and Tulare counties
→ 6
6. Flowers (1.5-)2-2.5 mm; tepals monomorphic; involucres 0.8-1.3 mm; s Sierra Nevada, Olancha Peak
E. wrightii
6. Flowers 3-4 mm; tepals dimorphic, outer globose; involucres 1.5-2 mm; Cottonwood, Last Chance, and Panamint mountains
E. gilmanii
7. Tepals dimorphic, outer often 2 times as wide as inner; scapes floccose to tomentose or lanate or nearly glabrous; common in e and s California
E. ovalifolium
7. Tepals monomorphic, or if somewhat dimorphic, flowers, involucres, and scapes glandular-pubescent; ec and ne California
→ 8
8. Perianths yellow or ochroleucous to reddish yellow, not white
→ 9
8. Perianths white to rose or pink, not yellow or ochroleucous (except sometimes yellow in E. shockleyi)
→ 11
9. Involucres glandular or glandular-hairy; scapes glandular; Sierra Nevada from Placer County to Fresno County and in desert ranges of Inyo and Mono counties, usually above 2500 m
E. rosense
9. Involucres glabrous or floccose, occasionally glandular; scapes glabrous or glandular; Sierra Nevada and Great Basin; often below 1900 m
→ 10
10. Leaf blades oblanceolate to elliptic or ovate to obovate, 1-2 × 0.5-1(-1.5) cm; scapes 0.5-1.5(-2) dm, glandular at least proximal to inflorescence; involucres floccose abaxially; clay soils, Lassen County
E. ochrocephalum
10. Leaf blades oblanceolate to spatulate, elliptic or ovate, 0.4-0.8(-1) × 0.15-0.4(-0.6) cm; scapes 0.2-0.8 dm, glabrous; involucres glabrous or sparsely floccose; volcanic soils, Lassen and Modoc counties
E. prociduum
11. Involucres glandular or pubescent to glandular-puberulent, membranous; c Sierra Nevada and White Mountains, Inyo and Mono counties, 3000-3900 m
E. gracilipes
11. Involucres glabrous or tomentose, rigid; s Sierra Nevada, Transverse Ranges, and desert ranges to the east from Mono County s to Los Angeles and San Bernardino counties, typically below 3000 m
→ 12
12. Perianths and achenes pubescent; Last Chance Range, Inyo and Mono counties
E. shockleyi
12. Perianths and achenes glabrous; s Sierra Nevada, Transverse Ranges, and desert ranges to the east from Mono County s to Los Angeles and San Bernardino counties
E. kennedyi
13. Involucres 2-10 or more per node or in heads
→ 14
13. Involucres 1 per node
→ 24
14. Tepals distinctly dimorphic, those of outer whorl to 2 times as wide as those of inner whorl
→ 15
14. Tepals essentially monomorphic, those of outer whorl ca. as wide as those of inner whorl
→ 16
15. Inflorescences cymose-umbellate or capitate; outer tepals globose; Inyo County
E. gilmanii
15. Inflorescences umbellate-cymose to cymose; outer tepals not globose; PlumasCounty n to Siskiyou and Modoc counties
E. strictum
16. Plants herbaceous or woody at base
→ 17
16. Plants usually shrubs
→ 20
17. Leaf blades lanceolate to lance-ovate, 4-15(-25) cm, villous and green on both surfaces; Sierra Nevada and Great Basin region, Tulare and Mono counties n
E. elatum
17. Leaf blades oblanceolate to oblong-ovate, ovate, or elliptic, usually 2-6 cm, tomentose abaxially, tomentose or floccose to subglabrous, or glabrous adaxially; widespread
→ 18
18. Involucres (4-)5-7 × 3-8(-10) mm; flowering stems and inflorescence branches glabrous, rarely floccose; inflorescences subcapitate to cymose; leaf blades densely tomentose abaxially, greenish and glabrate adaxially; plants forming large mats; Channel Islands
E. grande
18. Involucres (2.5-)3-5(-7) × (1.5-)2-4 mm; flowering stems and inflorescence branches glabrous, floccose, or tomentose; inflorescences capitate to umbellate or cymose; leaf blades variously lanate to tomentose on both surfaces or tomentose to floccose or glabrous adaxially; plants erect, occasionally forming large mats; mainland
→ 19
19. Involucres and flowering stems glabrous or, if tomentose, plants not along the immediate coast; leaf blades variously lanate to tomentose on both surfaces or tomentose, floccose, or glabrous adaxially; plants mostly erect, not forming dense mats; widespread
E. nudum
19. Involucres and flowering stems tomentose to floccose, rarely glabrous; inflorescences capitate, umbellate, or cymose; leaf blades whitish-lanate to tawny-tomentose on both surfaces, or tomentose to floccose or glabrous and green adaxially; plants forming dense mats; cliffs and bluffs along immediate coast from San Luis Obispo County n
E. latifolium
20. Leaf blades narrowly linear or nearly so to oblanceolate, shorter than 2 cm and leaves usually strongly fasciculate; s coastal and desert ranges
E. fasciculatum
20. Leaf blades linear-oblong to orbiculate or, if linear, longer than 2 cm and leaves not fasciculate; insular or coastal mesas and foothills
→ 21
21. Perianths glabrous; coastal and near-coast areas, Monterey County s to Los Angeles County
E. parvifolium
21. Perianths villous; coastal Santa Barbara s to Los Angeles County and insular
→ 22
22. Leaf blades linear to narrowly oblong, 2-4(-5) cm, white-tomentose abaxially, cinereous to glabrate adaxially, margins revolute; Santa Cruz, Santa Rosa, and Anacapa islands
E. arborescens
22. Leaf blades ovate or oblong-ovate to ovate or lanceolate to narrowly oblong, 1.5-10 cm, white-tomentulose or tomentose on both surfaces, margins not revolute; coastal regions, Santa Barbara s to Los Angeles County and on Santa Rosa, Santa Catalina, San Clemente, and Santa Barbara islands
→ 23
23. Leaf blades ovate, 1.5-3 × 1-2.5(-3) cm, white-tomentulose; inflorescences congested, capitate; involucres narrowly turbinate; coastal regions, Santa Barbara s to Los Angeles County, and on Santa Rosa islands
E. cinereum
23. Leaf blades oblong-ovate to ovate or lanceolate to narrowly oblong, 2-7(-10) × 1-5 cm, white-tomentose; inflorescences often open, cymose; involucres campanulate; Santa Catalina, San Clemente, and Santa Barbara islands
E. giganteum
24. Involucres disposed in elongate racemes at tips of inflorescence branches
→ 25
24. Involucres disposed at forks of branching system
→ 31
25. Involucres usually 6-7 mm; plants perennial herbs, (6-)12-18 dm; s Coast Ranges and Transverse Ranges south
E. elongatum
25. Involucres (0.8-)1-6 mm; plants shrubs, subshrubs, or herbs, (1-)1.5-5 dm; widespread
→ 26
26. Plants shrubs; Great Basin region, Mono and n Inyo counties
E. nummulare
26. Plants subshrubs or herbs; widespread
→ 27
27. Plants suffrutescent and much-branched basally; leaf blades oblanceolate to elliptic, 0.1-1 cm wide, margins often revolute
→ 28
27. Plants not suffrutescent basally; leaf blades rounded to broadly ovate, (0.3-)1-3.5(-4) cm wide, margins not revolute
→ 29
28. Involucres 0.7-4 mm; flowers 2-4 mm; perianth usually white to pink; widespread
E. wrightii
28. Involucres (4-)5-6 mm; flowers usually 4-5 mm; perianth ochroleucous to rose; Santa Lucia Mountains, Monterey County
E. butterworthianum
29. Leaf blades round, (0.3-)0.5-1.5 × (0.3-)1-1.5 cm; petioles 1-2 cm; involucres campanulate; Inyo Mountains and Panamint and Coso ranges, Inyo County
E. mensicola
29. Leaf blades elliptic, oblong, ovate, or obovate, 1.5-4.5(-5) × 1-3.5(-4) cm; petioles 1-7 cm; involucres turbinate or turbinate-campanulate; Inyo and White mountains, Mono and Inyo counties s to New York Mountains, San Bernardino County
→ 30
30. Leaf blades elliptic to oblong, (2-)2.5-4.5(-5) × 1.5-3.5(-4) cm; petioles (2-)3-7 cm; involucres turbinate-campanulate, 3-4 × 3-4 mm; White and Inyo mountains, Mono and Inyo counties
E. rupinum
30. Leaf blades elliptic to ovate or obovate, 1.5-4 × 1-2.5 cm; petioles 1-5 cm; involucres turbinate, 3-5 × 2-4 mm; White and Inyo mountains south to New York mountains
E. panamintense
31. Plants herbaceous perennials
→ 32
31. Plants subshrubs or shrubs
→ 33
32. Leaf blades round-ovate, 0.3-0.5(-1) × 0.3-0.5(-1) cm; Amador County
E. apricum
32. Leaf blades oblanceolate to elliptic or ovate, 1-6 × (0.3-)1-4 cm; widespread
E. nudum
33. Perianths pubescent
→ 34
33. Perianths glabrous
→ 36
34. Flowers (2.5-)3-4(-4.5) mm; perianth greenish yellow to yellow; involucres 1.5-2.5(-3) mm, 4-toothed; leaf blades (0.3-)0.5-1.5(-3.5) cm; Imperial and San Diego counties
E. deserticola
34. Flowers 3-6(-7) mm; perianth white; involucres 2-5 mm, 5-8-toothed; leaf blades (0.7-)1.2-5 cm; Del Norte and Plumas counties
→ 35
35. Involucres 3.5-5 mm; Del Norte County
E. pendulum
35. Involucres 2-3 mm; Plumas County
E. spectabile
36. Inflorescences usually compact, terminally cymose; involucres tomentose, floccose, or glabrous
→ 37
36. Inflorescences divaricatedly branched panicles or cymes; involucres glabrous
→ 38
37. Plants erect to spreading subshrubs in montane places, shrubs at lower elevations, 0.2-15 dm; leaf blades (0.3-)1-3.5 cm, margins not revolute, or if so, plants distinctly shrubby; e and s California
E. microthecum
37. Plants spreading or matted subshrubs of desert mountains, 0.5-1.5 dm; leaf blades 0.4-0.6 cm, margins revolute; New York Mountains, San Bernardino County
E. thornei
38. Outer tepals obovate to orbiculate; inflorescence branches green, dichotomous, ascending; mountain slopes, s Coast Ranges, Transverse Ranges, s Sierra Nevada, and desert ranges from Los Angeles and San Bernardino counties n to Monterey, San Benito, and Mono counties
E. heermannii
38. Outer tepals obovate; inflorescence branches grayish, mostly horizontal, tiered; desert valleys, Kern County s to e San Diego and eastward
E. plumatella

Key 2—British Columbia, Idaho, Oregon, and Washington

1. Plants subshrubs or shrubs
→ 2
1. Plants herbaceous, sometimes cespitose perennials
→ 5
2. Perianths villous; involucres 3.5-5 mm; peduncles (1-)3-10 cm; Josephine County, Oregon
E. pendulum
2. Perianths glabrous; involucres usually shorter than 3.5 mm; peduncles absent or shorter than 1.5 cm; widespread
→ 3
3. Leaves cauline; widespread
E. microthecum
3. Leaves basal; Deschutes, Harney, Klamath, Lake, and Malheur counties, Oregon
→ 4
4. Plants (3-)3.5-9 dm; perianths greenish white to pale yellow; Malheur County, Oregon
E. novonudum
4. Plants 0.3-1 dm; perianths yellow; Deschutes, Harney, Klamath, and Lake counties, Oregon
E. cusickii
5. Plants erect to spreading, decumbent, or prostrate, not forming compact, dense, cespitose mats; inflorescences branched
→ 6
5. Plants forming compact, dense, pulvinate to cespitose mats; inflorescences capitate, rarely branched
→ 14
6. Perianths usually hairy abaxially, sometimes sparsely so near base
→ 7
6. Perianths glabrous
→ 9
7. Leaf blades lanceolate to lanceolate-ovate, 4-15(-25) cm, loosely villous and green on both surfaces; e of Cascade Ranges in e Oregon and Washington e to Elmore and Washington counties, Idaho, and Siskiyou Mountains of s Oregon e into desert ranges of Lake County, Oregon
E. elatum
7. Leaf blades oblanceolate to elliptic or ovate, 1-5 cm, densely white-lanate to tomentose on both surfaces, sometimes floccose or glabrous and green adaxially; widespread
→ 8
8. Involucres and flowering stems glabrous or, if tomentose, then inflorescences compound-cymose; leaf blades lanate to tomentose on both surfaces, sometimes floccose or glabrous adaxially; plants not forming dense mats; widespread, s Oregon
E. nudum
8. Involucres and flowering stems tomentose; inflorescences capitate or cymose; leaf blades densely whitish-lanate or tawny-tomentose on both surfaces; plants forming dense mats; immediate coast, Curry County, Oregon
E. latifolium
9. Leaf blades linear to oblanceolate; perianths yellow; se Idaho
E. brevicaule
9. Leaf blades lanceolate, elliptic to ovate, or oval; perianths white, or if yellow then not of se Idaho
→ 10
10. Tepals dimorphic
→ 11
10. Tepals monomorphic
→ 12
11. Inflorescences usually not leafy-bracteate, umbellate-cymose to cymose, 1-20 cm; involucres 1 per node, rarely 2-5 per cluster, glabrous or tomentose; perianths white or yellow to rose or purple; petioles rarely twisted
E. strictum
11. Inflorescences generally leafy-bracteate at least at proximal nodes, cymose, 10-30 cm; involucres 1 per node, tomentose; perianths cream to reddish; petioles often twisted
E. niveum
12. Leaves white-tomentose on both surfaces; Malheur County, Oregon
E. novonudum
12. Leaves not white-tomentose on both surfaces, or if so then not of Malheur County, Oregon
→ 13
13. Involucres and flowering stems glabrous or, if tomentose, inflorescences compound-cymose; leaf blades oblanceolate to elliptic or ovate; plants not forming mats; widespread, s Oregon
E. nudum
13. Involucres and flowering stems tomentose; inflorescences capitate or cymose; leaf blades densely whitish-lanate or tawny-tomentose on both surfaces; plants forming dense mats; immediate coast, Curry County, Oregon
E. latifolium
14. Inflorescences umbellate, branching sometimes obscured by flowers
→ 15
14. Inflorescences capitate
→ 18
15. Perianths hairy abaxially; se Washington
E. codium
15. Perianths glabrous abaxially; c or se Idaho, or sc Oregon
→ 16
16. Outer tepals ca. 2 times as wide as inner ones; perianths bright white; c Idaho
E. ovalifolium
16. Outer tepals ca. as wide as inner ones; perianths yellow or ochroleucous; se Idaho or sc Oregon
→ 17
17. Involucres tomentose to floccose; perianths yellow or ochroleucous; leaf blades linear to narrowly oblanceolate, to 7 × 0.5 cm; se Idaho
E. brevicaule
17. Involucres glabrous; perianths yellow; leaf blades narrowly oblanceolate to spatulate, to 1.2 × 0.3 cm; sc Oregon
E. cusickii
18. Perianths hairy abaxially; achenes pubescent at least at beak; inflorescences typically branched but occasionally seemingly or actually capitate
→ 19
18. Flowers glabrous or glandular, not hairy; achenes glabrous, except on beaks; inflorescences usually capitate, rarely umbellate to cymose
→ 20
19. Perianths lemon yellow; se Washington
E. codium
19. Perianths white to rose or yellow; s Idaho
E. shockleyi
20. Involucres membranous
→ 21
20. Involucres rigid
→ 24
21. Perianths cream; se Idaho
E. mancum
21. Perianths pale yellow to yellow; c and w Idaho, or e Oregon
→ 22
22. Perianths pale yellow; flowering stems glandular-hairy; leaf blades white-tomentose and glandular on both surfaces; Wallowa County, Oregon, and Adams and Idaho counties, Idaho
E. scopulorum
22. Perianths yellow; flowering stems glandular or thinly floccose to tomentose; leaf blades tomentose on both surfaces or less so and grayish to greenish adaxially, not glandular; Blaine, Butte, Camas, Custer, Lemhi, and Owyhee counties, Idaho, or Malheur County, Oregon
→ 23
23. Flowering stems glandular or thinly floccose; involucres tomentose or glandular; Blaine, Butte, Camas, Custer, Lemhi, and Owyhee counties, Idaho
E. crosbyae
23. Flowering stems floccose to tomentose; involucres glabrous except for margins of teeth; Malheur County, Oregon
E. chrysops
24. Tepals dimorphic, those of outer whorl generally 2 times as wide as those of inner whorl or, if dimorphic but less than 2 times as wide, plants of subalpine or alpine habitats, or leaf blades elliptic to round and perianths white to cream or rose
E. ovalifolium
24. Tepals monomorphic, those of outer whorl ca. as wide as those of inner whorl or, if slightly dimorphic, plants not of subalpine or alpine habitats, or leaf blades oblanceolate to narrowly elliptic and perianths usually yellow
→ 25
25. Inflorescences of 1 involucre atop peduncle; inflorescence bracts absent; Beaverhead Mountains, Lemhi County, Idaho
E. soliceps
25. Inflorescences of 2-8 involucres atop scape; inflorescence bracts subtending cluster of involucres; widespread
→ 26
26. Perianths distinctly pustulose along midribs and base abaxially
→ 27
26. Perianths not pustulose abaxially
→ 28
27. Perianths yellow; Blaine, Butte, Camas, Custer, Lemhi, and Owyhee counties, Idaho
E. crosbyae
27. Perianths white to cream; Butte, Clark, Custer, and Lemhi counties, Idaho
E. mancum
28. Involucres turbinate, 2.5-4.5(-6) × 1.5-2.5(-4) mm; leaf blades (0.2-)1-10(-12)
→ 29
28. Involucres campanulate, 2-4 × 2-4 mm; leaf blades 0.5-1.5 cm
→ 30
29. Flowering stems to 1.4 dm, tomentose; se Idaho
E. brevicaule
29. Flowering stems (0.6-)1-4(-5) dm, glabrous or rarely slightly floccose; sw Idaho, se Oregon
E. ochrocephalum
30. Involucres (2-)3-4 × (2.5-)3-4 mm, glabrous or floccose only on teeth; flowers 2-3.5(-4) mm, perianth bright yellow; Harney, Lake, and Baker counties, Oregon
E. prociduum
30. Involucres 2-3.5 × 2-3.5 mm, floccose throughout; flowers 1.5-3 mm, perianth yellow; Harney and Lake counties, Oregon
E. crosbyae

Key 3—Nevada and Utah

1. Plants subshrubs or shrubs
→ 2
1. Plants herbs
→ 21
2. Perianths pubescent
→ 3
2. Perianths glabrous
→ 4
3. Leaves not fasciculate, blade lanceolate to elliptic or oblanceolate, tomentose or nearly so; Thousand Lake Mountain, Wayne County, Utah
E. corymbosum
3. Leaves usually fasciculate, blade usually oblanceolate, canescent on both surfaces or densely tomentose abaxially and canescent adaxially; s Nevada and sw Utah
E. fasciculatum
4. Involucres usually racemosely arranged along tips of inflorescence branches
→ 5
4. Involucres dichotomously arranged even at tips of inflorescence branches
→ 8
5. Flowering stems and inflorescence branches angled and ribbed or scabrous, or if round and smooth then rigid or stout, glabrous and with short, spinose lateral branches; s Nevada and Washington County, Utah
E. heermannii
5. Flowering stems and inflorescence branches not angled and ribbed or scabrellous or with short, spinose lateral branches, tomentose to floccose or, if glabrous, slender and flexible; widespread
→ 6
6. Leaves fasciculate, blade 0.2-1.5 × 0.25-0.7(-0.9) cm, oblanceolate to elliptic; wc and s Nevada, and Washington County, Utah
E. wrightii
6. Leaves not fasciculate, blade 1.5-3.5 × 0.2-0.8(-1.2) cm, linear-lanceolate or linear-oblanceolate to narrowly oblong; Nevada, s and e Utah
→ 7
7. Leaf blades usually linear-lanceolate to narrowly oblong or narrowly elliptic; inflorescence branches tomentose to floccose or glabrate, occasionally glabrous; e Utah
E. leptocladon
7. Leaf blades broadly oblanceolate to broadly elliptic; inflorescence branches usually tomentose; Nevada and s Utah
E. nummulare
8. Margins of leaf blades revolute or at least inrolled
→ 9
8. Margins of leaf blades usually plane
→ 12
9. Leaf blades (0.5-)2-6 cm; inflorescences densely branched, usually glabrous; involucres narrowly turbinate, glabrous; San Juan County, Utah
E. leptophyllum
9. Leaf blades 0.5-1.8(-2.5) cm; inflorescences usually sparsely branched, tomentose to floccose; involucres turbinate to turbinate-campanulate, tomentose to floccose or rarely glabrous; widespread
→ 10
10. Tepals monomorphic; widespread
E. microthecum
10. Tepals dimorphic; e Utah
→ 11
11. Plants 1-2.5 dm; leaf blades oblanceolate, usually thinly tomentose and grayish, rarely glabrous and green adaxially; involucres 2.5-4.5 mm wide; San Juan County, Utah
E. clavellatum
11. Plants 0.2-0.8 dm; leaf blades linear-oblanceolate to narrowly elliptic, white- to reddish- or tannish-tomentose adaxially; involucres 1.5-3 mm wide; Carbon, Emery, and Grand counties s to Garfield, San Juan, Sevier, and Wayne counties, Utah
E. bicolor
12. Inflorescences flat-topped and in tiers, branches zigzag; leaf blades tomentose on both surfaces; plants erect; s Clark County, Nevada
E. plumatella
12. Inflorescences usually open, not flat-topped, branches not zigzag; leaf blades variable but typically not tomentose on both surfaces; plants spreading to rounded, typically wider than tall; widespread
→ 13
13. Leaf apices sharply acute; leaf blades usually narrowly elliptic to elliptic, 0.2-1.2 cm wide
E. microthecum
13. Leaf apices acute to rounded; leaf blades lanceolate to oblanceolate or elliptic to oval, cordate, or nearly orbiculate, (0.2-)0.3-3(-3.5) cm wide
→ 14
14. Flowering stems and inflorescence branches tomentose to floccose, rarely subglabrous
→ 15
14. Flowering stems and inflorescence branches glabrous
→ 17
15. Leaf blades linear-lanceolate to lanceolate, 3.5-7(-9) × 0.3-0.6(-0.8) cm, densely white-tomentose abaxially, less so and greenish adaxially; leaf margins rarely crenulate; Duchesne County, Utah
E. hylophilum
15. Leaf blades lanceolate to oblanceolate or elliptic to nearly orbiculate, rarely cordate, 1-5 × (0.3-)0.5-3(-3.5) cm, densely silvery to white-, tannish-, or brownish-tomentose on both surfaces or less so or glabrous and green abaxially; leaf margins occasionally crenulate; not of Duchesne County, Utah
→ 16
16. Leaf blades densely white-, tannish-, or brownish-tomentose on both surfaces or less so or nearly glabrous and green abaxially, (0.5-)1-3(-4.5) cm; Clark County, Nevada, and s and e Utah
E. corymbosum
16. Leaf blades densely silvery-tomentose on both surfaces or rarely less so or subglabrous and greenish abaxially, 3-5 cm; Wellington area, Carbon and Emery counties, Utah
E. lancifolium
17. Leaf blades green and glabrous, rarely thinly floccose adaxially; flowers 3-4 mm, perianth yellow; San Rafael Desert, Emery and Wayne counties, Utah
E. smithii
17. Leaf blades tomentose to floccose at least on one surface; flowers 1.5-4 mm; perianth usually white, sometimes yellow, cream, or pink; widespread
→ 18
18. Involucres campanulate; leaf blades floccose adaxially, thinly floccose or glabrous abaxially; Nevada
E. heermannii
18. Involucres turbinate; leaf blades variable but always with one surface tomentose; Utah
→ 19
19. Perianths usually yellow to pale yellow, occasionally cream; leaf blades lanceolate to oblanceolate or elliptic, usually densely tomentose on both surfaces, sometimes less so and greenish adaxially; Washington County, Utah
E. corymbosum
19. Perianths white; leaf blades lanceolate or broadly elliptic, usually densely tomentose only abaxially; Millard or Uintah counties, Utah
→ 20
20. Plants spreading to somewhat sprawling subshrubs, (1.5-)2-4 dm; leaves commonly basal or sheathing up proximal 4 of flowering stems, blade broadly elliptic, 1-2(-2.5) cm; Millard County, Utah
E. ammophilum
20. Plants erect shrubs, 3-5 dm; leaves cauline, sheathing up proximal 1/ 2 of flowering stems, blade usually lanceolate, 3-6 cm; Uintah County, Utah
E. lonchophyllum
21. Plants cespitose, matted, or pulvinate; inflorescences usually capitate
→ 22
21. Plants herbaceous; inflorescences branched
→ 48
22. Perianths hairy
→ 23
22. Perianths glabrous, sparsely pilose, or glandular
→ 26
23. Achenes tomentose; widespread
E. shockleyi
23. Achenes glabrous; c and e Nevada, c, ne, and w Utah
→ 24
24. Flowers 2-2.5(-3) mm; perianth pale yellow to yellow; Emery and Garfield counties, Utah
E. aretioides
24. Flowers 3-4.5 mm; perianth white to rose; e Nevada and ne and w Utah
→ 25
25. Flowering stems spreading to prostrate, (0.5-)1.5-5(-8) cm; leaf blades narrowly elliptic, 0.3-1 × 0.1-0.2(-0.3) cm; e Nevada and w Utah
E. villiflorum
25. Flowering stems erect, 0.1-1 cm; leaf blades oblanceolate to elliptic, 0.3-0.4 × 0.07-0.1 cm; ne Utah
E. tumulosum
26. Tepals strongly dimorphic or, if only slightly so, leaf blades oval to rotund
E. ovalifolium
26. Tepals monomorphic or, if slightly dimorphic, leaf blades not oval to rotund
→ 27
27. Involucre tubes membranous
→ 28
27. Involucre tubes rigid
→ 31
28. Perianths greenish yellow to pale yellow, rarely yellow
→ 29
28. Perianths white to rose
→ 30
29. Involucres 2.5-3.5 mm, glabrous or sparsely pubescent with white hairs abaxially; flowers (2.5-)3-3.5 mm; perianths glabrous or sparsely glandular, usually greenish yellow or pale yellow; dry limestone and granitic montane slopes, Elko County and n White Pine County, Nevada
E. kingii
29. Involucres 2-2.5 mm, sparsely to densely tomentose with scattered glands along ribs; flowers (2-)2.5-3 mm; perianths sparsely glandular, yellow; moist, crusted, sandy, alkaline flats, Ruby Valley, Elko County, Nevada
E. argophyllum
30. Leaf blades oblanceolate to elliptic, (0.3-)1-1.5(-2) × (0.2-)0.3-0.6 cm, glandular and densely white-tomentose abaxially; involucres 5-7 per cluster, sparsely glandular to glandular-puberulent or pubescent; White Mountains, Esmeralda County, Nevada
E. gracilipes
30. Leaf blades oblanceolate to spatulate, 0.2-0.5(-1) × (0.1-)0.2-0.4 cm, glandular and densely white- or greenish-tomentose abaxially; involucres 2-4 per cluster, sparsely glandular-puberulent; Snake Range, White Pine County, Nevada
E. holmgrenii
31. Leaf blades linear to narrowly oblanceolate or narrowly elliptic, (1.5-)3-9(-12) × 0.1-0.5(-0.7) cm; n Utah
→ 32
31. Leaf blades lanceolate or oblanceolate to ovate, 0.2-3 × 0.05-1 cm; Nevada or c and n Utah
→ 33
32. Leaf blades white- to gray-tomentose abaxially, less so and grayish or occasionally greenish to thinly floccose and bright green adaxially; perianths usually yellow, occasionally ochroleucous; widespread
E. brevicaule
32. Leaf blades densely reddish- to brownish-lanate abaxially, less so to tomentose adaxially; perianths ochroleucous, rarely yellow; Cache and n Morgan counties, Utah
E. loganum
33. Scapes glandular or glandular-hairy
→ 34
33. Scapes glabrous or tomentose to floccose
→ 35
34. Involucres glandular and sparsely hairy; scapes densely glandular-hairy throughout, 0.1-0.9(-1.1) dm; wc Nevada
E. rosense
34. Involucres sparsely to densely floccose; scapes glandular or glandular only proximal to inflorescences, (0.5-)1-4.5(-5) dm; nw Nevada
E. ochrocephalum
35. Scapes glabrous
→ 36
35. Scapes tomentose to floccose
→ 40
36. Leaf margins crenulate or, if plane, leaf blades 1.5-6(-7) cm, scapes 8-25(-30) cm, and plants of s Utah
→ 37
36. Leaf margins plane
→ 38
37. Perianths usually greenish white to creamy white or pale yellowish white, rarely pale yellow or yellow; n Utah
E. brevicaule
37. Perianths white; s Utah
E. panguicense
38. Perianths white to pink or rose; Esmeralda County, Nevada
E. kennedyi
38. Perianths yellow; Humboldt and Washoe counties, Nevada
→ 39
39. Flowers pustulose; leaf blades obovate, (1-)1.5-2(-2.2) cm; Humboldt and Washoe counties, Nevada
E. crosbyae
39. Perianths not pustulose; leaf blades oblanceolate to spatulate or elliptic to ovate, 0.3-1(-1.5) cm; n Washoe and Humboldt counties, Nevada
E. prociduum
40. Leaf margins crenulate; Wasatch Mountains, Utah, above 3000 m
E. brevicaule
40. Leaf margins not crenulate; Nevada or, if in Utah, below 2800 m
→ 41
41. Perianths yellowish white or whitish to cream, glandular; Silver Peak Range, Esmeralda County, Nevada
E. tiehmii
41. Perianths cream or yellow, glabrous; not of Esmeralda County, Nevada
→ 42
42. Perianths yellow
→ 43
42. Perianths cream to white, pink, or rose
→ 45
43. Leaf blades narrowly oblanceolate to oblanceolate, (0.8-)1-4(-4.5) cm, densely grayish-tomentose abaxially, tomentose to floccose and grayish to green adaxially; Elko and White Pine counties, Nevada, and Box Elder, Rich, and Tooele counties, Utah
E. brevicaule
43. Leaf blades oblanceolate to elliptic or rarely ovate, 0.4-2(-2.5) cm, densely greenish- to white-tomentose on both surfaces, or densely greenish-white-tomentose abaxially, thinly tomentose and whitish green adaxially; n Nevada and nw Utah
→ 44
44. Perianths not pustulose; e Elko County, Nevada, and Box Elder, Juab, and Tooele counties, Utah
E. desertorum
44. Perianths pustulose; Washoe County s to Mineral County, e to Humboldt and w Elko counties, Nevada
E. crosbyae
45. Flowering stems 0.02-0.15 dm; leaf blades (0.2-)0.25-0.45(-0.7) × (0.07-)0.1-0.25 cm; San Francisco Mountains, Beaver County, Utah
E. soredium
45. Flowering stems 0.1-2 dm; leaf blades (0.5-)0.8-2(-2.3) × (0.2-)0.3-1.2(-1.8) cm; not in San Francisco Mountains, Beaver County, Utah
→ 46
46. Leaves sheathing flowering stem (1.5-)2-4 cm; Churchill Narrows,Lyon County, Nevada
E. diatomaceum
46. Leaves not sheathing flowering stem; not of Churchill County, Nevada
→ 47
47. Perianths not pustulose; leaf blades elliptic to obovate or suborbiculate, (0.7-)0.9-1.3(-2) × (0.3-)0.5-0.9(-1.1) cm; Elko, Eureka, Humboldt, Lander, and Pershing counties, Nevada
E. anemophilum
47. Perianths pustulose; leaf blades oblanceolate to spatulate or ovate, 0.5-1.5(-1.8) × (0.2-)0.3-0.5(-1) cm; House Range, Millard County, Utah
E. mancum
48. Flowers with stipelike bases; leaf blades obovate to rounded and lanate to tomentose; Esmeralda and Nye counties, Nevada
E. saxatile
48. Flowers without stipelike bases; leaf blades not obovate to rounded and densely lanate to tomentose; widespread
→ 49
49. Perianths usually hairy abaxially
→ 50
49. Perianths glabrous
→ 52
50. Plants matted; leaf blades 0.3-0.8 × 0.1-0.2 cm, margins revolute; to be expected in Daggett County, Utah
E. acaule
50. Plants not matted; leaf blades 1-15(-25) × 0.3-6 cm, margins plane; Nevada
→ 51
51. Leaf blades oblanceolate to elliptic, 1-4 × 0.3-2 cm, densely tomentose abaxially, tomentose to floccose or glabrous adaxially; w Nevada
E. nudum
51. Leaf blades lanceolate to lance-ovate, 4-15(-25) × 1.5-6 cm, loosely villous and green on both surfaces; nw and n Nevada
E. elatum
52. Inflorescences with involucres racemosely arranged
→ 53
52. Involucres not racemosely arranged
→ 57
53. Perianths pale yellow to yellow; flowering stems and inflorescence branches usually glabrous, rarely tomentose, occasionally fistulose; s Utah
E. zionis
53. Perianths white to rose; flowering stems and inflorescence branches usually tomentose, rarely glabrous, not fistulose; widespread
→ 54
54. Inflorescences with 5-20 or more racemosely arranged involucres along most of length of inflorescence branches; plants 3-8(-10) dm; e Nevada and Utah
E. racemosum
54. Inflorescences with 3-5 racemosely arranged involucres at tips of distalmost inflorescence branches; plants 1-5 dm; c and sw Nevada
→ 55
55. Leaf blades round, (0.3-)0.5-1.5 cm; involucres campanulate, 2-3(-4) mm; Sheep Range, Clark County, Nevada
E. mensicola
55. Leaf blades elliptic to oblong, ovate, or obovate, 1.5-4.5(-5) cm; involucres turbinate to turbinate-campanulate, 3-5 mm; Clark, Esmeralda, Lander, Lincoln, Mineral, and Nye counties, Nevada
→ 56
56. Plants 3-5 dm; leaf blades elliptic to oblong, (2-)2.5-4.5(-5) × 1.5-3.5(-4) cm, thinly tomentose abaxially, less so to floccose and greenish adaxially; Esmeralda, Lander, Lincoln, Mineral, and Nye counties, Nevada
E. rupinum
56. Plants 1.5-3 dm; leaf blades elliptic to ovate or obovate, 1.5-4 × 1-2.5 cm, white-tomentose abaxially, slightly less so and often greenish adaxially; w Esmeralda, sw Nye, and n Clark counties, Nevada
E. panamintense
57. Flowering stems and inflorescence branches usually tomentose to floccose
→ 58
57. Flowering stems and inflorescence branches usually glabrous
→ 61
58. Leaf blades linear or narrowly oblanceolate to narrowly elliptic or narrowly lanceolate, 0.1-0.5(-0.7) cm wide; n Utah
→ 59
58. Leaf blades lanceolate to elliptic or spatulate, 0.3-1.3 cm wide; c Utah
→ 60
59. Peduncles absent; plants 1-3.5 dm, tomentose; n Utah
E. brevicaule
59. Peduncles 0.2-1 cm; plants 0.5-0.8(-1) dm, thinly floccose or glabrous; e Emery and Grand counties, Utah
E. contortum
60. Perianths bright yellow; leaf blades elliptic, (0.8-)1-1.3 cm wide; Millard County, Utah
E. natum
60. Perianths ochroleucous or pale yellow; leaf blades lanceolate to narrowly elliptic or narrowly spatulate, 0.3-1 cm wide; Beaver, Iron, Juab, Millard, Piute, Sanpete and Sevier counties, Utah
E. spathulatum
61. Tepals dimorphic; plants forming loose mats; involucres 4-6 mm; inflorescences umbellate-cymose to cymose; n Nevada
E. strictum
61. Tepals usually monomorphic; plants not forming mats, plants of Utah with subcapitate to umbellate-cymose inflorescences; inflorescences usually cymose; widespread
→ 62
62. Inflorescences elongate, rather narrow; plants 2-3(-5) dm; involucres usually 3-5 mm; wc Nevada
E. nudum
62. Inflorescences spreading or, if narrow, plants of ne Utah; plants 0.4-4.5(-6) dm; involucres usually 1.5-3.5 mm; Utah. [63. Shifted to left margin.—Ed.]
→ 63
63. Leaf blades linear, 1.5-6 × 0.05-0.1 cm; Sevier County, Utah
E. mitophyllum
63. Leaf blades linear to oval, (0.5-)1-10(-12) × 0.1-0.7 cm; widespread
→ 64
64. Leaf blades linear to narrowly lanceolate, narrowly elliptic, or oblanceolate; n and ne Utah
→ 65
64. Leaf blades elliptic, spatulate, oblong, or ovate to round, or if oblanceolate, then plants of sw Utah
→ 68
65. Leaf blades 3-10(-12) cm, linear to narrowly oblanceolate; n and ne Utah
E. brevicaule
65. Leaf blades 1-3(-4) cm, linear to narrowly elliptic or lanceolate; ne Utah
→ 66
66. Leaf blades lanceolate, margins plane; inflorescences sparsely branched; perianths ochroleucous to pale yellow, rarely yellow; Uintah County, Utah
E. ephedroides
66. Leaf blades linear to narrowly elliptic, margins revolute or nearly so; inflorescences densely branched; perianths yellow; Duchesne, Emery, Grand, and Uintah counties
→ 67
67. Plants 1-3.5 dm; peduncles 0.1-0.2 cm; Duchesne and Uintah counties, Utah
E. viridulum
67. Plants 0.5-0.8(-1) dm; peduncles 0.2-1 cm; Emery and Grand counties, Utah
E. contortum
68. Leaf blades tomentose on both surfaces; Beaver and Millard counties, Utah
→ 69
68. Leaf blades tomentose abaxially, less so to floccose or glabrous adaxially; widespread
→ 71
69. Perianths ochroleucous to pale yellow, rarely yellow; flowers 3.5-4 mm; peduncles 0.2-1 cm; volcanic sands
E. artificis
69. Perianths white to ochroleucous; flowers 2.5-3 mm; peduncles absent; limestone gravel and outcrops
→ 70
70. Leaf blades lanceolate to narrowly elliptic or narrowly spatulate
E. spathulatum
70. Leaf blades ovate to round
E. eremicum
71. Leaf margins crenulate; leaves sheathing up stem; inflorescences subcapitate to cymose; plants spreading
→ 72
71. Leaf margins not crenulate; leaves usually basal; inflorescences cymose; plants usually erect
→ 73
72. Perianths greenish white to creamy white or pale yellowish white, rarely pale yellow or yellow; Wasatch Mountains, Box Elder and Weber counties, Utah
E. brevicaule
72. Perianths white; Bull Mountain, Garfield County, Utah
E. cronquistii
73. Flowering stems and inflorescence branches bright green; Kane and Washington counties, Utah
E. thompsoniae
73. Flowering stems and inflorescence branches usually gray to reddish or, if dark green, plants of wc Utah
→ 74
74. Leaf blades oblanceolate to narrowly lanceolate, 0.2-0.7 cm wide; San Juan and Uintah counties, Utah
E. lonchophyllum
74. Leaf blades elliptic to spatulate or broadly elliptic, 0.5-1(-1.5) cm wide; Carbon, Duchesne, Emery, Garfield, Grand, Piute, Sevier, and Uintah counties, Utah
→ 75
75. Peduncles (0.5-)1-3(-5) cm; Garfield, Piute, and Sevier counties, Utah
E. ostlundii
75. Peduncles absent; Carbon, Duchesne, Emery, Garfield, Grand, and Uintah counties, Utah
E. batemanii

Key 4—Arizona and New Mexico

1. Plants herbaceous perennials, sometimes cespitose and matted
→ 2
1. Plants shrubs or subshrubs
→ 11
2. Perianths pubescent
→ 3
2. Perianths glabrous
→ 5
3. Achenes glabrous; flowering stems and inflorescence branches glabrous; plants erect, (2-)3-6 dm; se New Mexico
E. havardii
3. Achenes villous-tomentose; flowering stems and inflorescence branches tomentose or floccose; plants erect, (0.5-)1-3.5 dm, or cespitose mats; n Arizona and n New Mexico
→ 4
4. Involucres (2-)4-6 mm, deeply 5-10-toothed; perianths white to rose or yellow; n Arizona and nw New Mexico
E. shockleyi
4. Involucres (2-)3-4 mm, 5-toothed; perianths yellow; ne Arizona and n New Mexico
E. lachnogynum
5. Tepals dimorphic; inflorescences usually capitate; n Arizona and nw New Mexico
E. ovalifolium
5. Tepals usually monomorphic; inflorescences not capitate; widespread
→ 6
6. Inflorescences virgate or racemose; involucres racemose along proximal inflorescence branches; plants usually erect, 3-8(-10) dm
→ 7
6. Inflorescences broadly cymose; involucres not racemose along proximal inflorescence branches; plants spreading to erect, 1-4(-6) dm
→ 8
7. Perianths white to pinkish; flowering stems and involucres usually tomentose to floccose; n Arizona and n New Mexico
E. racemosum
7. Perianths pale yellow to yellow or bright red; flowering stems and involucres usually glabrous, rarely tomentose; nw Arizona
E. zionis
8. Flowering stems and inflorescence branches tomentose; leaf blades elliptic to ovate or obovate, 1.5-4 × 1-2.5 cm; perianths white to whitish brown; Mohave County, Arizona
E. panamintense
8. Flowering stems and inflorescence branches glabrous; leaf blades usually linear to ovate or cordate to truncate, rarely reniform, (1-)3-8(-10) × 0.2-2.5(-3) cm; perianths white or yellow; widespread
→ 9
9. Leaf blades usually cordate to truncate, rarely reniform, (1-)1.5-2.5 cm, glabrous except for fine hairs on margins and veins; flowers 1-2 mm; perianth yellow; Eddy County, New Mexico
E. gypsophilum
9. Leaf blades linear to ovate, 1.5-8(-10) cm, tomentose to floccose on both surfaces, sometimes glabrous adaxially; flowers 2-3.5(-4) mm; perianth white or pale yellow to yellow; nw Arizona and n New Mexico
→ 10
10. Involucres 1 per node, turbinate, 2-3(-3.5) × 1-1.5(-2) mm; leaf margins plane or slightly revolute; Arizona
E. thompsoniae
10. Involucres 1 per node or 2-5 per cluster, turbinate to turbinate-campanulate, 2.5-4 × (1.3-)1.5-3.5(-4) mm; leaf margins plane or occasionally crenulate; New Mexico
E. lonchophyllum
11. Perianths pubescent
→ 12
11. Perianths glabrous
→ 13
12. Perianths white to pinkish; leaf blades usually oblanceolate, canescent adaxially; widespread, Arizona
E. fasciculatum
12. Perianths greenish yellow to yellow; leaf blades oblong-ovate to round-oblong or orbiculate, tomentose on both surfaces; Yuma County, Arizona
E. deserticola
13. Flowering stems and inflorescence branches angled and ridged or scabrous or, if round and smooth, glabrous, dark green, and with spinose lateral branches
E. heermannii
13. Flowering stems smooth, glabrous, floccose, or tomentose, grayish to greenish
→ 14
14. Involucres racemosely disposed at tips of inflorescence branches
→ 15
14. Involucres dichotomously arranged at tips of inflorescence branches
→ 17
15. Leaves fasciculate, blade 0.2-1.5 × 0.2-0.7(-0.9) cm, oblanceolate to elliptic; widespread
E. wrightii
15. Leaves not fasciculate, blade usually 1.5-3.5 × 0.2-0.8(-1.2) cm, linear-lanceolate or linear-oblanceolate to narrowly oblong or broadly elliptic; n Arizona and nw New Mexico
→ 16
16. Leaf blades linear-lanceolate to linear-oblanceolate to narrowly oblong or lanceolate to narrowly elliptic; inflorescence branches tomentose to floccose or glabrous; ne Arizona and San Juan County, New Mexico
E. leptocladon
16. Leaf blades broadly oblanceolate to broadly elliptic, rarely orbiculate; inflorescence branches tomentose to thinly floccose; nw Arizona
E. nummulare
17. Leaf margins revolute or at least inrolled or thickened
→ 18
17. Leaf margins not revolute or inrolled
→ 24
18. Leaf blades (0.5-)2-6 cm; inflorescences densely branched, thinly pubescent or glabrous; involucres narrowly turbinate, glabrous; n Arizona, nw New Mexico
E. leptophyllum
18. Leaf blades 0.2-1.8(-2.5) cm; inflorescences sparsely branched, usually tomentose to floccose; involucres turbinate to campanulate, tomentose to floccose or, rarely, glabrous; widespread
→ 19
19. Plants sprawling to decumbent subshrubs; inflorescences cymose-umbellate or capitate and reduced to single involucre; Coconino, se Yavapai, and nw Maricopa counties, Arizona
E. ripleyi
19. Plants erect to spreading subshrubs; inflorescences umbellate, umbellate-cymose, or cymose; widespread
→ 20
20. Tepals monomorphic
E. microthecum
20. Tepals dimorphic
→ 21
21. Leaf blades oblanceolate, 1-1.5(-2) cm, thinly tomentose and grayish adaxially, rarely glabrous; involucres turbinate-campanulate, 2.5-4.5 mm wide; nw San Juan County, New Mexico
E. clavellatum
21. Leaf blades linear to narrowly elliptic, 0.3-1 cm, floccose or glabrous and green adaxially; involucres narrowly turbinate to turbinate, 1-2 mm wide, or campanulate, 2.5-3.5 mm wide; Arizona
→ 22
22. Leaf blades linear, glabrous and green adaxially; involucres turbinate, 1.5-3(-3.5) × 1-2 mm; Verdi River Valley, c Yavapai County, Arizona
E. ericifolium
22. Leaf blades linear-oblanceolate to narrowly elliptic, floccose or glabrous and greenish adaxially; involucres narrowly turbinate and 1.5-3 × 1-1.5 mm or campanulate and 3-4.5 × 2.5-3.5 mm; not of Verdi River Valley, Arizona
→ 23
23. Flowers 1.5-2(-2.5) mm; involucres narrowly turbinate, 1-1.5 mm wide; plants 0.8-1.2(-1.5) dm; Apache, Coconino, ne Mohave, Navajo, and n Yavapai counties, Arizona
E. pulchrum
23. Flowers 3.5-4.5(-5) mm; involucres campanulate, 2.5-3.5 mm wide; plants 1-4(-5) dm; Cochise and Pima counties, Arizona
E. terrenatum
24. Inflorescences flat-topped and tiered, branches zigzag; leaf blades tomentose on both surfaces; plants erect, taller than wide; Mohave and w Yavapai counties, Arizona
E. plumatella
24. Inflorescences open, not flat-topped, branches not zigzag; leaf blades typically not tomentose on both surfaces; plants spreading to rounded, wider than tall; widespread. [25. Shifted to left margin.—Ed.]
→ 25
25. Leaf apices sharply acute; leaf blades usually narrowly elliptic, 0.1-0.2 cm wide; nw and nc Arizona
E. microthecum
25. Leaf apices acute to rounded; leaf blades lanceolate to oblanceolate, elliptic, or cordate, (0.2-)0.3-3 cm wide; widespread
→ 26
26. Flowering stems and inflorescence branches glabrous
→ 27
26. Flowering stems and inflorescence branches usually tomentose to floccose
→ 28
27. Leaf blades bright green and glabrous; Arizona
E. mortonianum
27. Leaf blades densely white-tomentose abaxially, sparsely tomentose to thinly floccose or glabrous and green adaxially; New Mexico
E. lonchophyllum
28. Tepals dimorphic
→ 29
28. Tepals monomorphic
→ 30
29. Leaf blades cordate, 1-2(-2.5) cm wide.
E. jonesii
29. Leaf blades linear, oblanceolate to spatulate or elliptic, 0.1-0.8 cm wide
E. heermannii
30. Leaf blades oblanceolate to oblong or obovate, (0.2-)0.3-0.7 cm wide, densely white-tomentose abaxially, white-floccose to glabrate or green and glabrous adaxially, margins plane; inflorescences usually dense; n New Mexico w to e San Juan County
E. effusum
30. Leaf blades usually lanceolate to oblanceolate or elliptic to nearly orbiculate, rarely cordate, (0.3-)0.5-3 cm wide, densely white-, tannish-, or brownish-tomentose on both surfaces or less so to nearly glabrous and green abaxially, margins crisped, occasionally crenulate; inflorescences usually open; n Arizona and nw New Mexico
E. corymbosum

Key 5—Alberta, Colorado, Montana, and Wyoming

1. Plants shrubs or subshrubs
→ 2
1. Plants herbs
→ 15
2. Leaf blades oblanceolate to lanceolate or elliptic, cordate to nearly orbiculate, apices rounded or nearly so
→ 3
2. Leaf blades linear to narrowly elliptic or narrowly lanceolate, apices sharply acute or nearly so
→ 5
3. Flowering stems and inflorescence glabrous, rarely tomentose
E. lonchophyllum
3. Flowering stems and inflorescence tomentose to floccose, glabrate, or subglabrous
→ 4
4. Inflorescences 10-30(-40) × 10-40 cm, floccose to glabrate or subglabrous; e Colorado
E. effusum
4. Inflorescences (1-)3-20 × 2-25(-30) cm, tomentose to floccose; w Colorado
E. corymbosum
5. Leaf margins plane or merely rolled
→ 6
5. Leaf margins usually revolute
→ 9
6. Leaf blades (0.5-)1-3 cm; widespread
→ 7
6. Leaf blades 3-6 cm; Colorado, sw Wyoming
→ 8
7. Leaf blades usually elliptic, (0.5-)1-2(-2.5) × (0.1-)0.2-0.6(-0.8) cm, densely to sparsely white-tomentose abaxially, less so to sparsely white-floccose adaxially; nw Colorado, sw Wyoming and sw Montana
E. microthecum
7. Leaf blades oblanceolate to oblong or obovate, (1-)1.5-3 × (0.2-)0.3-0.7 cm, densely white-tomentose abaxially, white-floccose to glabrate or green and glabrous adaxially; e Colorado, w Nebraska and se Wyoming to se Montana and sw South Dakota
E. effusum
8. Flowering stems and inflorescence branches tomentose to floccose
E. corymbosum
8. Flowering stems and inflorescence branches glabrous; Colorado
E. lonchophyllum
9. Leaf blades 1.5-4(-6) cm
→ 10
9. Leaf blades 0.5-1.8(-2.5) cm
→ 12
10. Flowering stems and inflorescence branches tomentose to floccose;Montezuma County, Colorado
E. leptocladon
10. Flowering stems and inflorescence branches glabrous or thinly pubescent; widespread
→ 11
11. Leaf blades linear to linear-oblanceolate, (0.03-)0.1-0.3 cm wide, greenish adaxially; inflorescences green and compactly branched; Montezuma County, Colorado
E. leptophyllum
11. Leaf blades narrowly lanceolate or oblanceolate to elliptic, 0.2-2 cm wide, grayish; inflorescences mostly grayish and openly branched; widespread
E. lonchophyllum
12. Tepals monomorphic
→ 13
12. Tepals dimorphic
→ 14
13. Leaf blades usually narrowly elliptic, 0.5-1.8(-2.5) cm, mostly white-floccose adaxially, margins slightly revolute; tepals connate proximal 1/ 4; widespread
E. microthecum
13. Leaf blades oblanceolate, 0.5-1.2(-1.5) cm, subglabrous or glabrous and green adaxially, margins tightly revolute; tepals connate proximal 1/ 2; Delta and Montrose counties, Colorado
E. pelinophilum
14. Flowers (2.5-)3-3.5 mm; leaf blades oblanceolate, thinly grayish-pubescent or glabrous and greenish adaxially, margins tightly revo- lute; plants 1-2.5 dm; Montezuma County, Colorado
E. clavellatum
14. Flowers 2.5-4(-4.5) mm; leaf blades linear-oblanceolate to narrowly elliptic, reddish- or tannish-tomentose adaxially, margins revolute; plants 0.2-0.8 dm; Mesa County, Colorado
E. bicolor
15. Perianths pubescent
→ 16
15. Perianths glabrous
→ 21
16. Achenes villous to tomentose
→ 17
16. Achenes glabrous
→ 18
17. Plants matted, 0.3-0.7 dm; w Colorado
E. shockleyi
17. Plants erect, not matted, 1-3.5 dm; e Colorado
E. lachnogynum
18. Perianths yellow; e Montana, ne Wyoming
E. brevicaule
18. Perianths white to rose; widespread
→ 19
19. Perianths pustulose; involucres campanulate, not rigid; Big Horn County, Wyoming, and Carbon County, Montana
E. mancum
19. Perianths not pustulose; involucres turbinate or campanulate, rigid; widespread
→ 20
20. Involucres narrowly turbinate; leaf blades 1-4 cm; Great Plains
E. pauciflorum
20. Involucres campanulate; leaf blades 0.3-0.4 cm; nw Colorado
E. tumulosum
21. Tepals dimorphic
→ 22
21. Tepals usually monomorphic
→ 23
22. Inflorescences compoundly branched
E. strictum
22. Inflorescences capitate or umbellate
E. ovalifolium
23. Inflorescences virgate or racemose, branches bearing 5-20(-30) racemosely arranged involucres; leaf blades (1.5-)2-6(-10) cm, elliptic to ovate or oval to nearly rotund; Colorado
E. racemosum
23. Inflorescences umbellate to cymose or capitate or if racemose, plants forming dense, compact mats; leaf blades 0.5-1.5 cm or, if longer, linear to oblanceolate, 3-10 cm, or spatulate to elliptic, (0.3-)1.5-4 cm; widespread. [24. Shifted to left margin.—Ed.]
→ 24
24. Plants erect to spreading, not forming mats
→ 25
24. Plants forming mats
→ 30
25. Inflorescences capitate or umbellate-cymose; c Colorado
E. brandegeei
25. Inflorescences cymose; n or w Colorado northward
→ 26
26. Leaf blades densely white-tomentose on both surfaces, elliptic; nw Colorado
E. batemanii
26. Leaf blades tomentose abaxially, thinly floccose and greenish or glabrous and green adaxially, linear to elliptic, lanceolate, or spatulate; n Colorado north
→ 27
27. Leaf blades linear to oblanceolate or spatulate, (1-)1.5-10 × 0.1-0.9(-1.2) cm, margins not revolute; widespread
E. brevicaule
27. Leaf blades usually linear to lanceolate, rarely narrowly elliptic, (0.5-)1-3(-4) × 0.1-0.2(-0.5) cm, margins often revolute; nw Colorado
→ 28
28. Peduncles absent; to be expected in Moffat County, Colorado
E. viridulum
28. Peduncles erect, 0.2-1.5 cm; Colorado
→ 29
29. Leaf blades linear to narrowly lanceolate, margins revolute; perianths yellow; flowering stems and inflorescence branches floccose to nearly glabrous; Garfield and Mesa counties, Colorado
E. contortum
29. Leaf blades lanceolate, margins plane; perianths ochroleucous or pale yellow or rarely yellow; flowering stems and inflorescence branches glabrous; Rio Blanco County, Colorado
E. ephedroides
30. Perianths usually yellow
→ 31
30. Perianths white to ochroleucous or rose
→ 32
31. Scapes and involucres glandular; w Montana
E. crosbyae
31. Scapes and involucres not glandular; sw Wyoming, nw Colorado
E. brevicaule
32. Perianths pustulose; leaf blades 0.4-1.5 cm; involucres tomentose; Montana, ne Wyoming
→ 33
32. Perianths not pustulose; leaf blades 1-6 cm; involucres usually glabrous except for hairs on teeth; widespread
→ 34
33. Involucres 2-5 per cluster, not rigid; flowering stem scapelike, inflorescence bracts 3-5; peduncles absent
E. mancum
33. Involucres 1 per node, rigid; flowering stems and inflorescence bracts absent; peduncles present
E. soliceps
34. Peduncles 0.1-0.4 cm; inflorescences cymose-umbellate; flowering stems glabrous or floccose to tomentose; leaf blades linear to linear-oblanceolate, (2-)3-6 × 0.1-0.3 cm; nc Colorado and se Wyoming
E. exilifolium
34. Peduncles absent; inflorescences capitate or subcapitate to cymose-umbellate; flowering stems glabrous or tomentose; leaf blades linear-oblanceolate to oblanceolate to lanceolate or narrowly spatulate to elliptic, 1-4(-5) × 0.1-1 cm; Great Plains or Rocky Mountains
→ 35
35. Flowering stems glabrous; Rocky Mountains, Colorado, above 2800 m
E. coloradense
35. Flowering stems tomentose; Great Plains, Montana to Colorado, below 1800 m
E. pauciflorum

Key 6—Manitoba, Saskatchewan, Great Plains States, and Texas

1. Plants shrubs or subshrubs
→ 2
1. Plants herbs
→ 6
2. Tepals strongly dimorphic; w Texas
E. suffruticosum
2. Tepals monomorphic; Great Plains, including Texas
→ 3
3. Leaf blades linear to linear-oblanceolate, 0.1-0.3 cm wide; wc Kansas
E. helichrysoides
3. Leaf blades oblanceolate to oblong, elliptic or obovate, 0.2-2.5 cm wide; widespread
→ 4
4. Leaf blades (1-)1.5-2.5 cm wide; Deaf Smith County, Texas
E. corymbosum
4. Leaf blades 0.2-0.7 cm wide; widespread
→ 5
5. Inflorescences cymose, with involucres not racemosely arranged; leaves not fasciculate; n Great Plains
E. effusum
5. Inflorescences virgate or somewhat cymose, with involucres racemosely arranged; leaves often fasciculate; w Texas
E. wrightii
6. Perianths glabrous; n Great Plains
→ 7
6. Perianths pubescent; Great Plains or Texas
→ 8
7. Perianths usually yellow, rarely white or cream
E. brevicaule
7. Perianths whitish brown to rose
E. pauciflorum
8. Perianths whitish brown to rose, sparsely pubescent; plants loosely matted; n Great Plains
E. pauciflorum
8. Perianths yellow, densely white-pubescent; plants not matted; s Great Plains or Texas
→ 9
9. Achenes villous to tomentose; sw Kansas, w Oklahoma, Texas
E. lachnogynum
9. Achenes glabrous; w Texas
E. havardii
Source FNA vol. 5, p. 224.
Parent taxa Polygonaceae > subfam. Eriogonoideae > Eriogonum
Subordinate taxa
E. acaule, E. ammophilum, E. anemophilum, E. apricum, E. arborescens, E. aretioides, E. argophyllum, E. artificis, E. batemanii, E. bicolor, E. brandegeei, E. breedlovei, E. brevicaule, E. butterworthianum, E. chrysops, E. cinereum, E. clavellatum, E. codium, E. coloradense, E. contortum, E. corymbosum, E. crocatum, E. cronquistii, E. crosbyae, E. cusickii, E. deserticola, E. desertorum, E. diatomaceum, E. effusum, E. elatum, E. elongatum, E. ephedroides, E. eremicum, E. ericifolium, E. exilifolium, E. fasciculatum, E. giganteum, E. gilmanii, E. gracilipes, E. grande, E. gypsophilum, E. havardii, E. heermannii, E. helichrysoides, E. holmgrenii, E. hylophilum, E. jonesii, E. kennedyi, E. kingii, E. lachnogynum, E. lancifolium, E. latifolium, E. leptocladon, E. leptophyllum, E. loganum, E. lonchophyllum, E. mancum, E. mensicola, E. microthecum, E. mitophyllum, E. mortonianum, E. natum, E. niveum, E. novonudum, E. nudum, E. nummulare, E. ochrocephalum, E. ostlundii, E. ovalifolium, E. panamintense, E. panguicense, E. parvifolium, E. pauciflorum, E. pelinophilum, E. pendulum, E. plumatella, E. prociduum, E. pulchrum, E. racemosum, E. ripleyi, E. rosense, E. rupinum, E. saxatile, E. scopulorum, E. shockleyi, E. smithii, E. soliceps, E. soredium, E. spathulatum, E. spectabile, E. strictum, E. suffruticosum, E. terrenatum, E. thompsoniae, E. thornei, E. tiehmii, E. tumulosum, E. villiflorum, E. viridulum, E. wrightii, E. zionis
Synonyms subg. Eucycla
Name authority (Nuttall) Kuntze: in T. E. von Post and O. Kuntze, Lex. Gen. Phan., 204. (1903)
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