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unarmed buckwheat, unarmed wild buckwheat

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

Habit Herbs, spreading, annual, 0.5–3 dm, glandular, greenish or reddish. Subshrubs, spreading to erect, infrequently polygamodioecious, 0.5–4 × 3–5(–6) dm, floccose or glabrous.
Stems

caudex absent;

aerial flowering stems mostly erect, solid, not fistulose, 0.1–0.5 dm, glandular.

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 and cauline;

basal: petiole 0.5–2 cm, glabrous, not or indistinctly winged, ciliate, blade spatulate, 1–4(–4.5) × 0.4–1.5(–1.8) cm, glabrous, margins ciliate;

cauline sessile, blade lanceolate, 0.3–1 × 0.1–0.3 cm, similar to basal blade.

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

cymose, open or diffuse, 5–25 × 5–30 cm;

branches glandular;

bracts 3, scalelike, 0.5–1.5 × 1–2 mm, occasionally semileaflike, 4–10(–12) × 1–5 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 or erect, straight, slender, 0.1–1 cm, glandular.

Involucres

turbinate, 1.5–1.9 × 1–1.2 mm, glabrous or hispidulous;

teeth 4, erect or nearly so, 0.8–1.2 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

4–6, 1.2–1.8 mm;

perianth pink to reddish, hirsutulous with stiff, white, hooked hairs;

tepals monomorphic, oblong;

stamens included, 1–1.5 mm;

filaments glabrous.

(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

brown, lenticular, 1.5–1.9 mm, glabrous;

beak not exserted beyond tepals.

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

Eriogonum inerme

Eriogonum sphaerocephalum

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

Varieties 2 (2 in the flora).

(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. Involucres glabrous; Coast and Transverse ranges, California, disjunct in Boise County, Idaho
var. inerme
1. Involucres hispidulous; Transverse Ranges and s Sierra Nevada, disjunct in Tuolumne County, California
var. hispidulum
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. 410. FNA vol. 5, p. 361.
Parent taxa Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Ganysma 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. 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. 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. inerme var. hispidulum, E. inerme var. inerme
E. sphaerocephalum var. fasciculifolium, E. sphaerocephalum var. halimioides, E. sphaerocephalum var. sphaerocephalum, E. sphaerocephalum var. sublineare
Synonyms Oxytheca inermis
Name authority (S. Watson) Jepson: Fl. Calif. 1: 406. (1914) Douglas ex Bentham: Trans. Linn. Soc. London 17: 407. (1836)
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