The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

Blue Mountain buckwheat, strict buckwheat

rock buckwheat, rock wild buckwheat, round-head buckwheat, round-head eriogonum

Habit Herbs, erect, loosely to densely matted, not scapose, 1–5 × 1–10 dm, tomentose or glabrous. Subshrubs, spreading to erect, infrequently polygamodioecious, 0.5–4 × 3–5(–6) dm, floccose or glabrous.
Stems

spreading to erect, with or without persistent leaf bases, up to 1/4 height of plant;

caudex stems absent or spreading to matted;

aerial flowering stems erect to spreading, slender, solid, not fistulose, 1–3 dm, tomentose or glabrous.

caudex spreading;

aerial flowering stems erect, slender, solid, not fistulose, arising at nodes of caudex branches and at distal nodes of short, non-flowering aerial branches, (0.3–)0.5–1 dm, thinly floccose or glabrous, with a whorl of 4–8 leaflike bracts ca. midlength or proximally, linear-oblanceolate to oblanceolate, 1–2 × 0.1–0.4 cm.

Leaves

basal, 1 per node;

petiole rarely twisted or curled, 1–6 cm, mostly tomentose;

blade elliptic to ovate, 0.5–2.5(–4) × (0.3–)0.5–1.5 cm, lanate, tomentose to floccose on both surfaces, sometimes sparsely tomentose to floccose and greenish or floccose to subglabrous or glabrous adaxially, margins plane.

in loose to congested basal rosettes;

petiole 0.05–0.3 cm, floccose or glabrous;

blade linear-oblanceolate, narrowly oblanceolate, or narrowly spatulate, 1–3(–4) × (0.1–)0.3–0.6(–1) cm, lanate or tomentose to floccose or glabrous, margins entire, plane or revolute.

Inflorescences

umbellate-cymose to cymose, 1–20 × 3–25 cm;

branches dichotomous, tomentose to floccose or less often glabrous;

bracts 3, scalelike, triangular, 1–3 mm.

capitate, compound-umbellate, or umbellate, 1–2 cm wide or 1–5 × 1–5 cm;

branches thinly floccose or glabrous;

bracts absent immediately below involucre.

Peduncles

absent.

Involucres

1 per node, rarely 2–5 per cluster, narrowly turbinate to turbinate-campanulate, 4–6 × 1.5–5 mm, tomentose or glabrous;

teeth 5, erect, 0.5–1.3 mm.

1 per node, turbinate-campanulate to campanulate, 3–4 × 2.5–4.5 mm;

teeth 6–10, lobelike, slightly reflexed, 1.5–3(–5) mm.

Flowers

3–5(–6) mm;

perianth yellow or white to rose or purple, glabrous;

tepals connate proximally, dimorphic, those of outer whorl elliptic to nearly orbiculate, 2–3 × 2–3 mm, those of inner whorl oblanceolate to oblong, 3–4 × 1–2 mm;

stamens included to slightly exserted, 2–5 mm;

filaments pilose proximally.

(5–)6–9 mm, including 1–2 mm stipelike base;

perianth pale to bright yellow or cream to ochroleucous, villous abaxially;

tepals monomorphic, obovate to oblong-ovate;

stamens exserted, 4–6 mm;

filaments pilose proximally.

Achenes

light brown to brown, 3–3.5 mm, glabrous.

light brown, 3–4 mm, glabrous except for sparsely pubescent beak.

Eriogonum strictum

Eriogonum sphaerocephalum

Distribution
from FNA
CA; ID; MT; NV; OR; WA
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; ID; NV; OR; WA
[WildflowerSearch map]
[BONAP county map]
Discussion

Varieties 4 (4 in the flora).

Eriogonum strictum, E. niveum, and E. ovalifolium form a complex of closely related species differing in leaf, inflorescence branching, and flower features. Variety proliferum appears to be the basal entity of the complex, approaching both E. niveum and E. ovalifolium var. pansum in its pubescence and branching pattern. Also, specimens of var. proliferum are sometimes difficult to differentiate from E. nudum var. oblongifolium. Careful observation, though, will permit well-made collections to be easily distributed among the individual species. An alternative taxonomy is to reduce all of the taxa to E. ovalifolium and recognize a series of subspecies and varieties. It is possible that additional study will show that E. strictum is sufficiently distinct from its tomentose to floccose counterparts to justify recognition of E. proliferum. In that case, both var. anserinum and var. greenei would be assigned to the latter species. Or, one could follow C. L. Hitchcock et al. (1955–1969, vol. 2) and recognize subsp. strictum as distinct from subsp. proliferum, with the latter consisting of varieties proliferum, anserinum, and greenei.

Members of the Eriogonum strictum are food plants for the Bauer’s dotted-blue butterfly (Euphilotes baueri).

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

Varieties 4 (4 in the flora).

The Piute of Nevada have used a decoction of the root of Eriogonum sphaerocephalum (either var. sphaerocephalum or var. halimoides) to treat colds and diarrhea (P. Train et al. 1941).

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

Key
1. Inflorescence branches glabrous
var. strictum
1. Inflorescence branches tomentose to floccose
→ 2
2. Perianths yellow
var. anserinum
2. Perianths white to rose or purple
→ 3
3. Leaf blades grayish-tomentose to floccose on both surfaces, or greenish-tomentose to floccose adaxially
var. proliferum
3. Leaf blades densely whitish-lanate to tomentose on both surfaces
var. greenei
1. Perianths bright yellow; inflorescences umbellate or compound-umbellate; ne California, sw Idaho, n and wc Nevada, e Oregon, and e Washington
var. sphaerocephalum
1. Perianths pale yellow to cream or ochroleucous; inflorescences umbellate, compound-umbellate, or capitate; ne California, sw or wc Idaho, c Oregon, and c Washington
→ 2
2. Leaf blades usually thinly floccose or glabrous on both surfaces; inflorescences umbellate or compound-umbellate; sw Idaho
var. fasciculifolium
2. Leaf blades tomentose on both surfaces, or floccose adaxially; inflorescence capitate or umbellate; ne California to nw Nevada, c Oregon to wc Idaho, and c Washington. [3. Shifted to left margin.—Ed.]
→ 3
3. Leaf blades usually narrowly oblanceolate to narrowly spatulate, margins plane; ne California to nw Nevada, c Oregon to wc Idaho, and c Washington
var. halimioides
3. Leaf blades linear-oblanceolate, margins usually revolute; nc Oregon, sc Washington
var. sublineare
Source FNA vol. 5, p. 317. FNA vol. 5, p. 361.
Parent taxa Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Eucycla Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Oligogonum
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. 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. umbellatum, 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
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. 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. umbellatum, 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. strictum var. anserinum, E. strictum var. greenei, E. strictum var. proliferum, E. strictum var. strictum
E. sphaerocephalum var. fasciculifolium, E. sphaerocephalum var. halimioides, E. sphaerocephalum var. sphaerocephalum, E. sphaerocephalum var. sublineare
Name authority Bentham: Trans. Linn. Soc. London 17: 414. (1836) Douglas ex Bentham: Trans. Linn. Soc. London 17: 407. (1836)
Web links