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goldencarpet buckwheat, goldencarpet wild buckwheat, wicker buckwheat

spreading buckwheat, spreading wild buckwheat

Habit Herbs, erect or prostrate to spreading, 0.5–6 dm, glabrous or occasionally tomentose, greenish to reddish. Shrubs, spreading, not scapose, (1.5–)2–5(–7) × 5–15 dm, grayish- to reddish-brown-tomentose to floccose and gray or, rarely, thinly floccose and greenish.
Stems

aerial flowering stems prostrate to erect, 0.2–2 dm, glabrous or occasionally tomen-tose.

spreading to erect, typically without persistent leaf bases, up to 1/2 height of plant;

caudex stems absent;

aerial flowering stems erect to spreading, slender, solid, not fistulose, 0.3–0.8 dm, floccose or glabrous.

Leaves

basal or basal and cauline;

basal: petiole 1–8 cm, floccose, blade oblong-ovate, reniform, or rounded to cordate, 0.5–5 × 0.5–3.5 cm, densely white-tomentose abaxially, floccose or glabrous and reddish or greenish adaxially;

cauline: petiole 0.5–3 cm, floccose, blade cordate to reniform or orbiculate, 0.5–3 × 0.5–3 cm, similar to basal blade.

cauline, 1 per node;

petiole 0.2–0.7 cm, tomentose to floccose;

blade 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, margins plane.

Inflorescences

cymose, occasionally distally uniparous due to suppression of secondary branches, open, 2–50 × 3–40 cm;

branches glabrous or occasionally tomentose;

bracts 1–3(–4) × 1–2 mm.

cymose, 10–30(–40) × 10–40 cm;

branches dichotomous, white-floccose to glabrate or subglabrous;

bracts 3, scalelike, triangular, 0.5–2(–5) mm.

Peduncles

absent or erect, straight, slender, 0.1–0.5 cm, glabrous.

absent or mostly erect, slender, 0.3–2.5 cm, floccose.

Involucres

terminal at tips of slender branchlets proximally or appressed to branches, cylindric or occasionally turbinate, 2–4 × 1.5–2.5 mm, glabrous or rarely floccose;

teeth 5, erect, 0.3–0.5 mm.

1 per node, turbinate, 1.5–2.5(–3) × 1–2 mm, tomentose to floccose;

teeth 5, erect, 0.3–0.6 mm.

Flowers

1–2.5 mm;

perianth white to rose or yellow, glabrous;

tepals monomorphic, obovate;

stamens included, 1–1.5 mm;

filaments glabrous.

2–4 mm;

perianth yellow, glabrous;

tepals connate proximal 1/4, essentially monomorphic, elliptic to obovate;

stamens mostly exserted, 2–4.5 mm;

filaments sparsely pilose proximally.

Achenes

light brown, 3-gonous, 1–2 mm.

brown, 2–2.5 mm, glabrous.

Eriogonum luteolum

Eriogonum effusum

Phenology Flowering Jun–Sep.
Habitat Sandy to rocky slopes and flats, mixed grassland and sagebrush communities, juniper and montane conifer woodlands
Elevation 1200-2500 m (3900-8200 ft)
Distribution
from FNA
CA; OR
[WildflowerSearch map]
[BONAP county map]
from FNA
CO; MT; NE; NM; SD; WY
[WildflowerSearch map]
[BONAP county map]
Discussion

Varieties 4 (4 in the flora).

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

Eriogonum effusum is rather common on the northern Great Plains and along the eastern slope of the Rocky Mountains in central and eastern Colorado, southeastern Montana, western Nebraska, northern New Mexico, southwestern South Dakota, and southeastern Wyoming. Some specimens from Chaffee County, Colorado, are thinly floccose and greenish (Atwood & Welsh 29689, BRY) and thus similar to E. leptocladon. A collection from Pyramid Lake, Washoe County, Nevada (Frandsen & Brown 182, NESH) is clearly mislabeled. A roadside collection of E. effusum gathered near Little America, Sweetwater County, Wyoming, in 1961 (G. Mason 4025, ASU) was an introduction that has not persisted.

The spreading wild buckwheat is occasionally merged with Eriogonum microthecum even though the two are morphologically distinct and their ranges do not overlap. Plants in New Mexico are sometimes difficult to distinguish from the related E. leptocladon var. ramosissimum. The species is the food plant for the Rita dotted-blue butterfly (Euphilotes rita). A hybrid between Eriogonum effusum and E. pauciflorum has been named E. ×nebraskense Rydberg [E. multiceps Nees subsp. nebraskense (Rydberg) S. Stokes; E. pauciflorum Pursh var. nebraskense (Rydberg) Reveal]. The hybrid is known from Weld County, Colorado; Cheyenne and Kimball counties, Nebraska; and Converse and Platte counties, Wyoming.

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

Key
1. Plants prostrate to spreading, 0.5-3 dm; involucres 3-4 mm, often terminal on elongated branchlets; leaves basal and cauline; serpentine soil; w Alameda and s Marin counties, California
var. caninum
1. Plants erect, 2-6 dm; involucres 2-3.5 mm, appressed to inflorescence branches; leaves basal, sometimes also cauline; serpentine or granitic soils; San Mateo, Santa Clara, and Mariposa counties, California, n to sw and sc Oregon
→ 2
2. Involucres 2-3 mm; flowers 2-2.5 mm; granitic soils; Sierra Nevada, Alpine and Tuolumne counties, California
var. saltuarium
2. Involucres 3-3.5 mm; flowers 1-2 mm; serpentine soils; Coast Ranges and lower foothills of Sierra Nevada, San Mateo, Santa Clara, and Mariposa counties, California, n to sw and sc Oregon
→ 3
3. Flowers 1.8-2 mm; Coast Ranges, w California from San Mateo and Santa Clara counties n to sw and sc Oregon
var. luteolum
3. Flowers 1-1.5(-1.8) mm; e California from Mariposa County to Plumas County
var. pedunculatum
Source FNA vol. 5, p. 420. FNA vol. 5, p. 248.
Parent taxa Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Oregonium Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Eucycla
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. 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. 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. 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. luteolum var. caninum, E. luteolum var. luteolum, E. luteolum var. pedunculatum, E. luteolum var. saltuarium
Synonyms E. vimineum var. luteolum E. microthecum var. effusum
Name authority Greene: Pittonia 3: 200. (1897) Nuttall: Proc. Acad. Nat. Sci. Philadelphia 4: 15. (1848)
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