Flora of North America species comparison

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Eriogonum umbellatum

Eriogonum subg. Oligogonum

sulfur buckwheat, sulfurflower, sulphur buckwheat, sulphur flower, sulphur-flower buckwheat, sulphur-flower wild buckwheat
Habit Herbs, subshrubs, or shrubs, cespitose, matted or spreading, sometimes erect, often polygamo-dioecious, (0.2–)1–12(–20) × (0.5–)1–12(–20) dm, glabrous or tomentose. Herbs, shrubs, or subshrubs, cespitose, matted or spreading to erect, polycarpic perennials, synoecious or polygamodioecious, rarely dioecious, lanate to tomentose, floccose, or glabrous occasionally sericeous; taproot woody.
Stems

caudex spreading;

aerial flowering stems spreading to erect or nearly so, slender, solid, not fistulose, arising at nodes of caudex branches and at distal nodes of short, nonflowering aerial branches, (0.1–)0.5–3(–4) dm, without a whorl of bracts at midlength.

prostrate to erect, with persistent leaf bases, glabrous, pubescent, or glandular;

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

aerial flowering stems prostrate or decumbent to erect, slender to stout, usually solid or hollow, sometimes fistulose, not disarticulating in ringlike segments proximally, arising at nodes of caudex branches, at distal nodes of aerial branches or, rarely, directly from the root.
Leaves

in loose to compact basal rosettes;

petiole 0.1–3(–4) cm, mostly tomentose to floccose or glabrous;

blade oblong-ovate or oblanceolate to elliptic to oval, 0.3–3(–4) × 0.1–2.5 cm, densely lanate to tomentose or floccose abaxially, tomentose to floccose or glabrous adaxially, occasionally glabrous on both surfaces, margins entire, plane or rarely wavy.

persistent through the growing season or longer, tufted at tips of caudices or whorled at base of stems in rosettes;

blade lanate, tomentose, floccose, villous, sericeous, or glabrous.
Inflorescences

umbellate or compound-umbellate, rarely subcapitate or capitate, 3–25 × 2–18 cm;

branches tomentose to floccose or glabrous, rarely with whorl of bracts ca. midlength;

bracts 3–several, semileaflike at proximal node, 0.3–2.5 × 0.2–1.8 cm, usually scalelike distally, 1–5 × 0.5–3 mm.

simple- to compound-umbellate, usually open and spreading, occasionally reduced and subcapitate to capitate;

branches absent or round and smooth, tomentose to floccose or glabrous;

bracts usually 2–10 sometimes more, scalelike, semileaflike, or leaflike.
Peduncles

absent (or sometimes technically erect and slender, being that portion of “aerial flowering stem” above a whorl of leaflike bracts about midlength; not treated as a distinct structure here).
Involucres

1 per node, turbinate to campanulate, 1–6 × (1–)1.5–10 mm, tomentose to thinly floccose or glabrous;

teeth 6–12, lobelike, reflexed, 1–4(–6) mm.

1 per node, rarely 2–3 per cluster, not appressed to inflorescence branches, turbinate to campanulate;

teeth 5–10 or more, erect or lobelike and spreading to reflexed.
Flowers

2–10(–12) mm, including (0.7–)1.3–2 mm stipelike base;

perianth various shades of white, yellow, or red, glabrous;

tepals monomorphic, usually spatulate to obovate;

stamens exserted, 2–8 mm;

filaments pilose proximally.

bisexual or unisexual, attenuate at base, stipelike base 0.1–3 mm;

perianth various shades of white, cream, yellow, pink, or reddish, glabrous or pubescent abaxially, glabrous adaxially;

tepals connate proximally 1/4–1/3 their length, monomorphic or dimorphic;

stamens usually exserted, occasionally included;

filaments pilose proximally, very rarely glabrous.
Achenes

light brown to brown, 2–7 mm, glabrous except for sparsely pubescent beak.

light to dark brown, not winged, 3-gonous, glabrous or pubescent only on beak.
Seeds

embryo straight or curved.

Eriogonum umbellatum

Eriogonum subg. Oligogonum
Distribution
from FNA
AZ; CA; CO; ID; MT; NV; OR; UT; WA; WY; AB; BC
[WildflowerSearch map]
[BONAP county map]
w North America (including n Mexico)
Discussion

Varieties 41 (41 in the flora).

Eriogonum umbellatum is a widespread and exceedingly variable species rivaling Astragalus lentiginosus Douglas ex Hooker in complexity. Only the variety majus is sometimes recognized at the species rank (as E. subalpinum).

In the following key and descriptions, reference is made to “glabrous” leaf surfaces. This is a function of both age and power of observation. High-power magnification may show some exceedingly fine hairs that are not readily observable to the naked eye. Furthermore, new leaves that ultimately will be “glabrous” will have some fine-tomentose pubescence that becomes less obvious (or even wholly inconspicuous) as the blade expands and matures. Here, the term “glabrous” is used to refer to leaves that are not obviously hairy and are typically bright green on both surfaces when the plant is at full anthesis.

There are several reported uses of sulphur flower in the enthobotany literature, mostly without an indication of the variety. J. B. Romero (1954) indicated that in California, where most of the variants are found, an infusion of the flowers is used for ptomaine poisoning, and M. L. Zigmond (1981) stated that the Kawaiisu used mashed flowers as a salve for gonorrheal sores. E. V. A. Murphey (1959), who worked with P. Train et al. (1941), reported that in Nevada members of the species (most likely var. nevadense) were used in the treatment of colds and stomachaches; J. H. Steward (1933) reported the same uses among the Owens Valley Piute in California. Train and his group noted that poultices of leaves and sometimes roots were used for lameness or rheumatism. In Oregon, leaves of var. ellipticum were used in a poultice to soothe pain, especially that resulting from burns (F. V. Coville 1897; L. Spier 1930). Most of the reports associated with the Navajo or Diné people probably relate to the use of var. subaridum. L. C. Wyman and S. K. Harris (1951) found the species used as a disinfectant or an emetic. The Cheyenne people employed a mixture of powdered stems and flowers to halt lengthy menses (G. B. Grinnell 1923; J. A. Hart 1981). According to A. Johnston (1987), the Blackfoot made a tea from boiled leaves.

The cythera metalmark butterfly (Apodemia mormo cythera) is found in association with a few varieties of sulphur flower (G. F. Pratt and G. R. Ballmer 1991). More commonly seen with the species are the Rocky Mountain dotted-blue (Euphilotes ancilla) and lupine blue (Plebeius lupini).

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

Species 35 (34 in the flora).

Only Eriogonum turneri Reveal is not treated here; it is related to E. jamesii var. undulatum, and is known only from gypsum outcrops in Nuevo León, Mexico.

(Discussion copyrighted by Flora of North America; reprinted with permission.)
Key
1. Inflorescences compound-umbellate, or with at least some branches seemingly with whorl of bracts about midlength
→ 2
1. Inflorescences umbellate, not compound-umbellate or with any branches seemingly with whorl of bracts about midlength
→ 22
2. Inflorescence branches with a whorl of bracts at midlength (see also E. umbellatum var. polyanthum)
→ 3
2. Inflorescence branches without a whorl of bracts at midlength, bracts restricted to base of inflorescence or involucres
→ 4
3. Perianths bright yellow; flowers 7-10 mm; Sierra Nevada, c California
var. torreyanum
3. Perianths cream or whitish; flowers 4-7 mm; Warner Mountains, se Oregon and ne California
var. glaberrimum
4. Flowers 7-10(-12) mm; shrubs 5-15(-20) × 5-20 dm; inflorescences branched 2-4 times; Humboldt and Trinity counties, California
var. speciosum
4. Flowers 3-8 mm; matted herbs or subshrubs, or, if shrubby, inflorescences branched 4 or more times, or not of Humboldt and Trinity counties, California
→ 5
5. Perianths cream, whitish, or pale yellow to greenish yellow, becoming reddish brown to rose or pink
→ 6
5. Perianths bright yellow, not becoming reddish brown to rose or pink
→ 7
6. Perianths yellow, becoming reddish brown to rose or pink, with large reddish spot on each midrib; plants spreading to somewhat prostrate mats; se California, s Nevada
var. versicolor
6. Perianths cream, whitish, or pale yellow to greenish yellow, without large reddish spot on midrib; plants subshrubs or shrubs; nc Arizona, se California, s Nevada, s Utah
var. juniporinum
7. Leaf blades thinly floccose, glabrous, or densely lanate to tomentose on both surfaces at anthesis (see also E. umbellatum var. munzii, s California)
→ 8
7. Leaf blades thinly to densely tomentose or lanate abaxially, less so to floccose, nearly glabrous, or glabrous adaxially (rarely both surfaces tomentose in E. umbellatum var. munzii, s California)
→ 13
8. Leaf blades densely lanate on both surfaces; wc California
var. bahiiforme
8. Leaf blades lanate to tomentose abaxially, tomentose to densely floccose adaxially, sometimes thinly floccose or glabrous on both surfaces; nw or ec California, Intermountain West, or Pacific Northwest.
→ 9
9. Leaf blades lanate to tomentose abaxially, thinly tomentose to floccose and greenish adaxially; nw California
→ 10
9. Leaf blades usually thinly floccose or glabrous on both surfaces; not of nw California
→ 11
10. Leaf blades 0.3-0.7 cm wide; involucral lobes 1-3 mm; plants of serpentine soils; Glenn, Lake, Mendocino, Sonoma, Tehama, and Trinity counties, California
var. smallianum
10. Leaf blades (0.5-)0.8-1.8(-2) cm wide; involucral lobes (3-)4-6 mm; plants of nonserpentine soils; Siskiyou County,California
var. lautum
11. Leaf blades thinly floccose on both surfaces, or glabrous and green adaxially (rarely glabrous on both surfaces in s Utah, or tomentose abaxially in se Utah); e and s California to sw Colorado and ne Arizona
var. subaridum
11. Leaf blades glabrous on both surfaces; e Idaho, ne Oregon, se Washington, and ec California
→ 12
12. Herbs; leaf blades broadly elliptic, 1-1.5 cm wide; e Idaho, ne Oregon, and se Washington
var. devestivum
12. Subshrubs or shrubs; leaf blades oblanceolate to narrowly elliptic, 0.3-1 cm wide; s Mono, Inyo, and ne Tulare counties, California
var. chlorothamnus
13. Plants densely branched, shrubs; w foothills, Sierra Nevada, n California
→ 14
13. Plants usually matted herbs or more openly and sparsely branched subshrubs or shrubs; mountains, Sierra Nevada, c and n California, wc Nevada, or Siskiyou and Trinity mountains, nw California (but not on the western foothills), sw Oregon, n Arizona, Colorado, Idaho, Montana, or Washington
→ 15
14. Leaf blades white-tomentose abaxially; inflorescences branched 1-2(-3) times, branches thinly floccose or glabrous, central branch sometimes seemingly with a whorl of bracts ca. midlength; Butte, Plumas, and Sierra counties
var. polyanthum
14. Leaf blades rusty-lanate to tomentose abaxially; inflorescences branched 3-4 time, branches tomentose to floccose, central branch without a whorl of bracts ca. midlength; Butte County
var. ahartii
15. Flowering stems mostly sparsely floccose or glabrous.
→ 16
15. Flowering stems usually tomentose or floccose, rarely nearly glabrous at maturity
→ 18
16. Leaf blades usually narrowly elliptic, 0.3-1(-1.3) cm wide; plants subshrubs or spreading mats; California, Nevada, Oregon
→ 17
16. Leaf blades oblong-ovate to elliptic or oval, 1-1.5(-2) cm wide; plants compact mats; n Arizona
var. cognatum
17. Leaf margins plane; flowering stems without a single leaflike bract ca. midlength; Sierra Nevada, e California, wc Nevada
var. furcosum
17. Leaf margins often finely wavy; flowering stems often with a single leaflike bract ca. midlength; Siskiyou and Trinity mountains, nw California, sw Oregon
var. argus
18. Leaf blades usually broadly elliptic to oval
→ 19
18. Leaf blades elliptic
→ 20
19. Leaf blades gray abaxially; c Colorado
var. ramulosum
19. Leaf blades white abaxially; n California
var. lautum
20. Leaf blades 1-1.5 cm wide, usually glabrous adaxially; Idaho, w Montana, Oregon, and e Washington
var. ellipticum
20. Leaf blades 0.3-1 cm wide, usually floccose adaxially; California
→ 21
21. Leaf blades 0.3-0.7 cm wide; nw California
var. smallianum
21. Leaf blades 0.5-1 cm wide; s California
var. munzii
22. Perianths usually whitish or cream to red, occasionally yellow
→ 23
22. Perianths bright yellow (pale yellow in some individuals of var. vernum in Nevada)
→ 27
23. Leaf blades densely lanate on both surfaces; perianths lemon yellow to yellowish red; San Gabriel and San Bernardino mountains, e Los Angeles and w San Bernardino counties, California
var. minus
23. Leaf blades tomentose to floccose or glabrous adaxially, sometimes glabrous on both surfaces at full anthesis; perianths not lemon yellow or yellowish red; not of e Los Angeles or w San Bernardino counties, California
→ 24
24. Leaf blades glabrous on both surfaces; s Idaho and sw Montana to w Wyoming, ne Nevada, and n Utah
var. desereticum
24. Leaf blades densely floccose to tomentose or lanate at least abaxially at full anthesis; widespread.
→ 25
25. Leaf blades densely lanate abaxially, glabrous and olive green to bright green adaxially; plants compact mats; perianths cream; Rocky Mountains to Cascade Range
var. majus
25. Leaf blades densely floccose to tomentose abaxially, less so or glabrous and green adaxially; plants spreading mats, rarely compact; perianths pale yellow to cream or whitish, rarely greenish white or yellow, becoming reddish brown to rose or pink, with large reddish spots on each midrib; Rocky Mountains to Sierra Nevada.
E. umbellatumvar. dichrocephalum
26. Perianths pale yellow to cream or whitish, rarely greenish white; leaf blades usually greenish adaxially; se Oregon and e California to w Montana, s Idaho, w Wyoming, c Nevada, and n Utah
var. dichrocephalum
26. Perianths yellow, becoming reddish brown to rose or pink, with large reddish spot on each midrib; leaf blades usually reddish adaxially; se California, s Nevada
var. versicolor
27. Umbels with branches usually longer than 2.5 cm.
→ 28
27. Umbels with branches usually shorter than 2.5 cm (immature specimens should be keyed through the opposing couplet as well)
→ 36
28. Leaf blades glabrous on both surfaces at full anthesis, occasionally with some individual blades thinly floccose abaxially
var. aureum
28. Leaf blades at least thinly tomentose or lanate abaxially
→ 29
29. Leaf blades thinly tomentose to thinly floccose on both surfaces, or glabrous adaxially
→ 30
29. Leaf blades densely white-lanate or tomentose abaxially, less so to floccose or glabrous adaxially
→ 33
30. Plants matted herbs
→ 31
30. Plants subshrubs or shrubs
→ 32
31. Leaf blades broadly elliptic to ovate, (0.8-)2-3(-3.5) × (0.7-)1-2(-2.5) cm; s Idaho, ne Nevada, wc Wyoming
var. stragulum
31. Leaf blades narrowly elliptic, 0.7-2.5 × 0.3-1 cm; nw Arizona
var. mohavense
32. Flowers 4-7 mm; Cali-fornia, n Nevada, se Oregon
var. nevadense
32. Flowers (5-)6-10 mm; n Nye County, Nevada
var. vernum
33. Subshrubs 3-5 dm; non-serpentine soils; n California and sc Oregon
var. dumosum
33. Herbs (0.7-)1-4.5(-5) dm; Rocky Mountains or, if in California and Oregon, often on serpentine soils
→ 34
34. Plants usually compact mats; nonserpentine soils; Rocky Mountains, sw Montana and e Idaho to Colorado, s and w Wyo-ming, and n Utah
var. umbellatum
34. Plants spreading to prostrate mats; often on serpentine soils; n California and sw Oregon.
→ 35
35. Flowering stems 1-2.5(-4) dm; leaf blades 0.5-2(-3.5) cm; flowers 6-8(-9) mm; 400-1700(-2100) m
var. goodmanii
35. Flowering stems 0.5-1.5 dm; leaf blades 0.5-1(-1.5) cm; flowers 3-6 mm; 1700-2800 m
var. humistratum
36. Plants prostrate, mostly in montane to subalpine or alpine communities.
→ 37
36. Plants erect to slightly spreading, not prostrate, usually not in subalpine or alpine communities
→ 39
37. Leaf blades glabrous on both surfaces at full anthesis
var. porteri
37. Leaf blades tomentose at least abaxially at full anthesis
→ 38
38. Leaf blades narrowly elliptic, 0.3-0.6(-1) × 0.2-0.4(-0.6) cm, tomentose abaxially, slightly less so and greenish adaxially; s Sierra Nevada and White Mountains, Mono, Inyo, and Tulare counties, California
var. covillei
38. Leaf blades broadly elliptic, 0.5-1.5(-2.5) × 0.5-1.2(-1.5) cm, tomentose or glabrous and olive green adaxially; n Cascade Range, Benton, Clackamas, Hood River, and Wasco counties, Oregon, and Kittitas and Yakima counties, Washington
var. haussknechtii
39. Leaf blades glabrous on both surfaces, sometimes with marginal hairs at full anthesis
→ 40
39. Leaf blades lanate to tomentose or floccose at least abaxially at full anthesis.
→ 41
40. Leaf blades without marginal hairs; se Oregon, Idaho, and Nevada to w Montana, Wyoming, Colorado, and Utah
var. aureum
40. Leaf blades with marginal hairs; Cascade Range, Washington
var. hypoleium
41. Leaf blades thinly tomentose abaxially, less so to floccose or glabrous and green adaxially; Sierra Nevada and Great Basin ranges
var. nevadense
41. Leaf blades densely lanate to tomentose abaxially; widespread, generally not in Great Basin ranges.
→ 42
42. Mature leaf blades lanate to tomentose on both surfaces; Yellowstone National Park, Wyoming
var. cladophorum
42. Mature leaf blades densely lanate or tomentose abaxially, less so to floccose or glabrous and greenish adaxially; w United States
→ 43
43. Larger leaf blades usually 0.3-1.5(-2) cm, usually elliptic to oblong; plants subshrubs or herbs
→ 44
43. Larger leaf blades 1-3(-3.5) cm, elliptic to ovate; plants subshrubs, or compact or spreading mats
→ 45
44. Leaf blades usually elliptic; non-serpentine soils; ne California, se Oregon, sw Idaho, n Nevada
var. modocense
44. Leaf blades elliptic to oblong; serpentine outcrops; nw California 107aa. Eriogonum umbellatum var. nelsoniorum
→ 43
45. Plants subshrubs; n Cascade Range, Washington
var. sandbergii
45. Plants compact or spreading mats; Rocky Mountains, Sierra Nevada, Transverse, and Argus ranges, California, Colorado, Idaho, Montana, Utah, and Wyoming
→ 46
46. Leaf blades elliptic to ovate, densely white-lanate abaxially; Rocky Mountains, sw Montana and e Idaho to s Colorado, w and s Wyoming, and s Utah
var. umbellatum
46. Leaf blades elliptic, densely grayish-lanate abaxially; s Sierra Nevada, Transverse Ranges, and Argus Range, California
var. canifolium
1. Involucral teeth lobelike, at least half as long as tube, usually reflexed or spreading
→ 2
1. Involucral teeth not lobelike, much shorter than tube, erect or nearly so
→ 14
2. Perianths pubescent abaxially
→ 3
2. Perianths glabrous abaxially
→ 8
3. Flowering stems (actually scapes) without subtending bracts on stem or below involucre; e California to se Oregon, s Idaho, sw Montana, w Wyoming, Nevada, Utah, and nw Arizona
E. caespitosum
3. Flowering stems with whorl of subtending bracts at base of umbel, near middle of stem, or near middle of branches
→ 4
4. Involucres usually more than 1 per, subtended by (2-)3-several leafy bracts at base of umbel; inflorescences compound-umbellate or umbellate, occasionally with whorl of bracts midlength on central branch of an umbel; flowering stem usually without whorl of bracts near middle
→ 5
4. Involucre 1 per inflorescence, not immediately subtended by leafy bracts; inflorescences capitate; flowering stems with whorl of bracts near middle
→ 6
5. Flowers (5-)6-9 mm; perianth bright or pale yellow or ochroleucous to cream; leaf blades lanate to tomentose, floccose, or glabrous on both surfaces; plants 0.5-4 dm; ne California to e Washington, s Idaho, and n Nevada
E. sphaerocephalum
5. Flowers 4-5 mm; perianth bright yellow; leaf blades densely tomentose on both surfaces; plants 2.5-5 dm; n California
E. tripodum
6. Leaf blades tomentose or lanate adaxially; e Washington to n and ec California, and nw and ne Nevada
E. douglasii
6. Leaf blades thinly tomentose to nearly glabrous and green adaxially; widespead
→ 7
7. Leaf blades usually linear-oblanceolate or narrowly oblanceolate to narrowly spatulate; n California and nw Nevada to sw Idaho, Oregon, and c Washington
E. sphaerocephalum
7. Leaf blades oblanceolate to elliptic; s Sierra Nevada in Tulare County, California
E. twisselmannii
8. Inflorescences capitate, without subtending bracts immediately below involucre; flowering stems with a whorl of leafy bracts ca. midlength; perianths yellow
→ 9
8. Inflorescence umbellate or compound-umbellate, subtended by leafy bracts immediately below umbel; flowering stems occasionally with an additional whorl of bracts ca. midlength; perianths various shades of white, yellow, or rose
→ 10
9. Leaf blades 0.5-1.5(-2) cm, densely tomentose on both surfaces, or subglabrous and pale green adaxially; plants erect or rounded herbs or subshrubs, occasionally matted; Sierra Nevada from Nevada County to Frenso County
E. prattenianum
9. Leaf blades (0.3-)0.5-0.8 cm, sparsely floccose to glabrate and bright green or olive green adaxially; plants matted herbs; Scott Mountain and Mt. Eddy region, Siskiyou and Trinity counties, California
E. siskiyouense
10. Flowering stems usually with whorl of leafy bracts ca. midlength; leaf blades usually linear to oblanceolate; s British Columbia and Washington to w Montana s to ne California, Idaho, n Nevada, Wyoming, c Utah, and nw Colorado
E. heracleoides
10. Flowering stems without a whorl of leafy bracts ca. midlength (present in E. umbellatum var. argus); leaf blades variable; equally widespread, extending to s California and n Arizona
→ 11
11. Stipelike bases of flowers 0.1-0.4 mm
→ 12
11. Stipelike bases of flowers 0.7-2 mm
→ 13
12. Flowers 5-7 mm; achenes 4.5-6 mm; flowering stems prostrate to decumbent or weakly erect; inflorescences subcapitate to umbellate, infrequently 2-umbellate; n California, sw Oregon, and wc Nevada
E. lobbii
12. Flowers 7-9 mm; achenes 6-8 mm; flowering stems erect or nearly so; inflorescences 2-umbellate; wc Nevada
E. robustum
13. Leaf blades 0.3-3(-4) cm; flowering stems not fistulose; w North America
E. umbellatum
13. Leaf blades (2-)7-25 cm; flowering stems occasionally fistulose; nw Idaho n to California, Oregon, Washington
E. compositum
14. Perianths pubescent abaxially
→ 15
14. Perianths usually glabrous abaxially
→ 25
15. Leaf blades pilose or hirtellous to glabrescent abaxially
→ 16
15. Leaf blades tomentose abaxially
→ 17
16. Leaf blades pilose, 1-3(-3.5) cm; perianths cream to pale yellow; flowers 3-6 mm; ec California, wc Nevada
E. latens
16. Leaf blades hirtellous to glabrescent, 0.5-2(-2.5) cm; perianths bright yellow; flowers 3-3.5(-4) mm; Del Norte and Siskiyou counties, California
E. hirtellum
17. Flowering stems with whorl of 6-10(-12) bracts ca. midlength; leaf blades silky-villous to sericeous adaxially; se Washington to ne Oregon and sw Idaho
E. thymoides
17. Flowering stems without whorl of bracts ca. midlength; leaf blades not silky-villous to sericeous adaxially; widespread
→ 18
18. Perianths white to rose; inflorescences subtended by 2 bracts; flowering stems weakly erect to ascending or prostrate; s British Columbia and Washington to n California to w Montana
E. pyrolifolium
18. Perianths white to cream or yellow; inflorescences subtended by 3-10 or more bracts; flowerings stem weakly erect or erect to ascending; widespread
→ 19
19. Perianths white to cream; e Arizona, Colorado, sw Kansas, New Mexico, w Texas
E. jamesii
19. Perianths pale to bright yellow; n Arizona and Colorado n to Alaska and Canada
→ 20
20. Inflorescences capitate or subcapitate to umbellate or, if compound-umbellate, plants of e Utah, Colorado, and nw New Mexico; plants matted, often cespitose, perennials usually shorter than 3 dm; Colorado Plateau, Rocky Mountains, and n Great Plains from n Arizona and New Mexico to Alaska and Canada
→ 21
20. Inflorescences compound-umbellate; plants not matted, taller than 3 dm or, if 1.5-3 dm, then plants of n Texas; se New Mexico, n Texas, nw Virginia, and e West Virginia
→ 23
21. Achenes glabrous; perianths pale yellow; sw Alberta and nw Montana
E. androsaceum
21. Achenes sparsely pubescent on beak; perianths yellow; widespread
→ 22
22. Inflorescences compound-umbellate or, if umbellate or capitate, not of distribution of E. flavum; Colorado Plateau, s Rocky Mountains and w edge of Great Plains from s Wyoming to n Arizona and n New Mexico
E. arcuatum
22. Inflorescences subcapitate or umbellate; n Great Plains and n Rocky Mountains, Wyoming and Nebraska north to Canada and Alaska, west to e Oregon and Washington 133. Eriogonum flavum
→ 20
23. Leaf blades 4-8 cm wide; nw Virginia, e West Virginia.
E. allenii
23. Leaf blades 1-3.5 cm wide; se New Mexico, n Texas
→ 24
24. Plants 4-5 dm; leaf blades (2.5-)3-6.5 cm; se New Mexico
E. wootonii
24. Plants 1.5-3.5(-4) dm; leaf blades (2-)4-12(-15) cm; n Texas
E. correllii
25. Inflorescences not immediately subtended by bracts; flowering stems seemingly with whorl of bracts near middle (portion below whorl technically is a flowering stem, whereas portion above whorl but below solitary involucre technically is a peduncle); California
→ 26
25. Inflorescences immediately subtended by whorl of bracts; flowering stems without a whorl of bracts near middle; California, w Nevada, s Oregon, disjunct in Washington
→ 29
26. Perianths whitish to pinkish or rose-red; leaf blades silky-tomentose and silvery abaxially, 0.1-0.3(-0.4) cm wide; Red Mountain, Mendocino County, California
E. kelloggii
26. Perianths yellow; leaf blades tomentose abaxially, 0.2-2(-3) cm wide; not of Mendocino County, California
→ 27
27. Flowering stems (0.3-)0.4-0.6 dm; leaf blades 1-2(-3) cm wide; Mt. Eddy and Scott Mountain, Siskiyou and Trinity counties, California
E. alpinum
27. Flowering stems 0.5-3 dm; leaf blades 0.2-0.7(-0.8) cm wide; not of Mt. Eddy and Scott Mountain, Siskiyou and Trinity counties, California
→ 28
28. Perianths sparsely pubescent abaxially; involucral teeth 5-8, 0.5-1.5 mm; North Coast Ranges, Trinity and Tehama counties, California
E. libertini
28. Perianths glabrous; involucral teeth 8-10, 1-3 mm; Sierra Nevada, Nevada County to Frenso County, California
E. prattenianum
29. Perianths chalky white, white to rose, or creamy yellow to pale yellowish; stipelike bases of flowers 0.1-0.4 mm
→ 30
29. Perianths yellow to brownish or sulphur yellow, ochroleucous, or cream and sometimes suffused with blush of pinkish red to maroon, rarely white; stipelike bases of flowers 0.3-1.5 mm
→ 32
30. Perianths chalky white; flowers 2.5-3.5 mm; involucres (2-)2.5-3.5(-4) mm; Fresno and Tulare counties, California
E. polypodum
30. Perianths white to rose or creamy yellow to pale yellowish; flowers 5-9 mm; n California, wc Nevada
→ 31
31. Flowers 5-7 mm; achenes 4.5-6 mm; flowering stems prostrate to decumbent or weakly erect; inflorescences subcapitate to umbellate, infrequently 2-umbellate; n California, sw Oregon, and wc Nevada
E. lobbii
31. Flowers 7-9 mm; achenes 6-8 mm; flowering stems erect or nearly so; inflorescences 2-umbellate; wc Nevada
E. robustum
32. Plants dioecious, with morphologically different pistillate and staminate plants in fruit
→ 33
32. Plants synoecious, without morphologically different plants in fruit
→ 35
33. Leaf blades glabrate and bright green to olive green adaxially; ne California, wc Nevada, s Oregon, disjunct to Yakima County, Washington
E. marifolium
33. Leaf blades lanate to tomentose on both surfaces, usually not green adaxially; Sierra Nevada or Siskiyou and Trinity mountains, California, Oregon, and Nevada
→ 34
34. Pistillate inflorescences capitate, umbellate after fertilization; leaf blades oblong to oblong-ovate or spatulate, 0.5-1.5 × 0.3-0.7 cm, tomentose; petioles (0.3-)0.5-1 cm; Sierra Nevada of ec California and wc Nevada
E. incanum
34. Pistillate inflorescences usually persistently capitate, rarely umbellate after fertilization; leaf blades elliptic to ovate, (0.5-)1-2 × 0.5-1.5 cm, lanate; petioles 0.7-3 cm; Siskiyou and Trinity mountains, nw California and sw Oregon
E. diclinum
35. Perianths white, cream, ochroleucous, pale yellow, or rarely yellow; involucres villous
→ 36
35. Perianths sulphur yellow; involucres tomentose
→ 37
36. Flowering stems 0.4-4 dm; inflorescences compound-umbellate; perianths cream, pale yellow, or rarely yellow; Sierra Nevada, Placer County to Shasta County, or n Coast Ranges, Shasta and Trinity counties to Siskiyou County, California
E. ursinum
36. Flowering stems 0.2-0.6(-1) dm; inflorescences subcapitate; perianths white to ochroleucous; n Coast Ranges, Sonoma and Lake counties, California
E. nervulosum
37. Inflorescences not immediately subtended by bracts; flowering stems seemingly with a whorl of bracts near middle (portion below whorl is flowering stem, portion above whorl but below solitary involucre is peduncle); flowers 5-8 mm; n Coast Ranges in Trinity and Tehama counties, California
riogonum libertini
37. Inflorescences subtended by a whorl of bracts immediately below umbel or head of several involucres; flowering stems not with a whorl of bracts near middle; flowers 3-6 mm; Del Norte, Siskiyou, Trinity, and Tehama counties, California, n to Curry and Josephine counties, Oregon
→ 38
38. Leaf blade margins not revolute, blade oblong to obovate, (0.4-)0.8-1.3 cm wide; plants matted; n Coast Ranges, Del Norte, Siskiyou, Trinity, and Tehama counties, California, to Curry and Josephine counties, Oregon
E. ternatum
38. Leaf blade margins revolute, blade narrowly elliptic to narrowly oblong, 0.3-0.6(-0.8) cm wide; plants subshrubs; Trinity and Siskiyou counties, California
E. congdonii
Source FNA vol. 5, p. 335. FNA vol. 5, p. 331.
Parent taxa Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Oligogonum Polygonaceae > subfam. Eriogonoideae > Eriogonum
Sibling taxa
E. abertianum, E. acaule, E. alatum, E. aliquantum, E. allenii, E. alpinum, E. ammophilum, E. ampullaceum, E. androsaceum, E. anemophilum, E. angulosum, E. annuum, E. apiculatum, E. apricum, E. arborescens, E. arcuatum, E. aretioides, E. argillosum, E. argophyllum, E. arizonicum, E. artificis, E. atrorubens, E. baileyi, E. batemanii, E. bicolor, E. bifurcatum, E. brachyanthum, E. brachypodum, E. brandegeei, E. breedlovei, E. brevicaule, E. butterworthianum, E. caespitosum, E. capillare, E. cernuum, E. chrysops, E. cinereum, E. cithariforme, E. clavatum, E. clavellatum, E. codium, E. collinum, E. coloradense, E. compositum, E. concinnum, E. congdonii, E. contiguum, E. contortum, E. correllii, E. corymbosum, E. covilleanum, E. crocatum, E. cronquistii, E. crosbyae, E. cusickii, E. darrovii, E. dasyanthemum, E. davidsonii, E. deflexum, E. deserticola, E. desertorum, E. diatomaceum, E. diclinum, E. divaricatum, E. douglasii, E. eastwoodianum, E. effusum, E. elatum, E. elegans, E. elongatum, E. ephedroides, E. eremicola, E. eremicum, E. ericifolium, E. esmeraldense, E. evanidum, E. exaltatum, E. exilifolium, E. fasciculatum, E. flavum, E. fusiforme, E. giganteum, E. gilmanii, E. glandulosum, E. gordonii, E. gossypinum, E. gracile, E. gracilipes, E. gracillimum, E. grande, E. greggii, E. gypsophilum, E. havardii, E. heermannii, E. helichrysoides, E. hemipterum, E. heracleoides, E. hieracifolium, E. hirtellum, E. hirtiflorum, E. hoffmannii, E. holmgrenii, E. hookeri, E. howellianum, E. hylophilum, E. incanum, E. inerme, E. inflatum, E. intrafractum, E. jamesii, E. jonesii, E. kelloggii, E. kennedyi, E. kingii, E. lachnogynum, E. lancifolium, E. latens, E. latifolium, E. lemmonii, E. leptocladon, E. leptophyllum, E. libertini, E. lobbii, E. loganum, E. lonchophyllum, E. longifolium, E. luteolum, E. maculatum, E. mancum, E. marifolium, E. mensicola, E. microthecum, E. mitophyllum, E. mohavense, E. molestum, E. mortonianum, E. multiflorum, E. natum, E. nealleyi, E. nervulosum, E. nidularium, E. niveum, E. nortonii, E. novonudum, E. nudum, E. nummulare, E. nutans, E. ochrocephalum, E. ordii, E. ostlundii, E. ovalifolium, E. palmerianum, E. panamintense, E. panguicense, E. parishii, E. parvifolium, E. pauciflorum, E. pelinophilum, E. pendulum, E. pharnaceoides, E. plumatella, E. polycladon, E. polypodum, E. prattenianum, E. prociduum, E. pulchrum, E. pusillum, E. pyrolifolium, E. racemosum, E. reniforme, E. ripleyi, E. rixfordii, E. robustum, E. rosense, E. roseum, E. rotundifolium, E. rubricaule, E. rupinum, E. salicornioides, E. saxatile, E. scabrellum, E. scopulorum, E. shockleyi, E. siskiyouense, E. smithii, E. soliceps, E. soredium, E. spathulatum, E. spectabile, E. spergulinum, E. sphaerocephalum, E. strictum, E. subreniforme, E. suffruticosum, E. temblorense, E. tenellum, E. ternatum, E. terrenatum, E. thomasii, E. thompsoniae, E. thornei, E. thurberi, E. thymoides, E. tiehmii, E. tomentosum, E. trichopes, E. tripodum, E. truncatum, E. tumulosum, E. twisselmannii, E. ursinum, E. vestitum, E. villiflorum, E. vimineum, E. viridescens, E. viridulum, E. viscidulum, E. visheri, E. watsonii, E. wetherillii, E. wootonii, E. wrightii, E. zionis
Subordinate taxa
E. umbellatum var. ahartii, E. umbellatum var. argus, E. umbellatum var. aureum, E. umbellatum var. bahiiforme, E. umbellatum var. canifolium, E. umbellatum var. chlorothamnus, E. umbellatum var. cladophorum, E. umbellatum var. cognatum, E. umbellatum var. covillei, E. umbellatum var. desereticum, E. umbellatum var. devestivum, E. umbellatum var. dichrocephalum, E. umbellatum var. dumosum, E. umbellatum var. ellipticum, E. umbellatum var. furcosum, E. umbellatum var. glaberrimum, E. umbellatum var. goodmanii, E. umbellatum var. haussknechtii, E. umbellatum var. humistratum, E. umbellatum var. hypoleium, E. umbellatum var. juniporinum, E. umbellatum var. lautum, E. umbellatum var. majus, E. umbellatum var. minus, E. umbellatum var. modocense, E. umbellatum var. mohavense, E. umbellatum var. munzii, E. umbellatum var. nevadense, E. umbellatum var. polyanthum, E. umbellatum var. porteri, E. umbellatum var. ramulosum, E. umbellatum var. sandbergii, E. umbellatum var. smallianum, E. umbellatum var. speciosum, E. umbellatum var. stragulum, E. umbellatum var. subaridum, E. umbellatum var. torreyanum, E. umbellatum var. umbellatum, E. umbellatum var. vernum, E. umbellatum var. versicolor, E. umbellatumvar. dichrocephalum
E. allenii, E. alpinum, E. androsaceum, E. arcuatum, E. caespitosum, E. compositum, E. congdonii, E. correllii, E. diclinum, E. douglasii, E. heracleoides, E. hirtellum, E. incanum, E. jamesii, E. kelloggii, E. latens, E. libertini, E. lobbii, E. marifolium, E. nervulosum, E. polypodum, E. prattenianum, E. pyrolifolium, E. robustum, E. siskiyouense, E. sphaerocephalum, E. ternatum, E. thymoides, E. tripodum, E. twisselmannii, E. umbellatum, E. ursinum, E. wootonii, riogonum libertini
Name authority Torrey: Ann. Lyceum Nat. Hist. New York 2: 241. (1827) Nuttall: J. Acad. Nat. Sci. Philadelphia, n. s. 1: 166. (1848)
Web links 
Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).



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