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Davidson buckwheat, Davidson's buckwheat, Davidson's wild buckwheat

San Pedro River wild buckwheat

Habit Herbs, erect, 1–5 dm, glabrous, greenish to grayish. Shrubs, sprawling to erect, not scapose, 1–4(–5) × (1–)2–6(–9) dm, thinly tomentose or floccose to subglabrous, greenish.
Stems

aerial flowering stems erect, 0.5–1.5(–2) dm, glabrous.

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

caudex stems absent;

aerial flowering stems erect or nearly so, slender, solid, not fistulose, 0.05–0.3 dm, thinly tomentose.

Leaves

basal;

petiole 1–5 cm, floccose;

blade round to reniform, (0.3–)1–2(–4) × (0.3–)1–2(–4) cm, densely white-tomentose abaxially, floccose to glabrate and mostly greenish adaxially.

cauline, fasciculate;

petiole 0.05–0.1 cm, glabrous;

blade linear-oblanceolate or linear-elliptic, 0.3–0.8(–1) × (0.05–)0.1–0.2 cm, densely white-tomentose abaxially, thinly floccose or glabrous and greenish adaxially, margins rolled.

Inflorescences

cymose, occasionally distally uniparous due to suppression of secondary branches, open, 5–40 × 5–35 cm;

branches straight or nearly so, infrequently inwardly curved distally, glabrous;

bracts 1–3 × 1–2 mm.

cymose, compact, 1–3 × 1–3 cm;

branches dichotomous, thinly tomentose;

bracts 3, scalelike, triangular, (0.5–)1–2 mm.

Peduncles

absent.

absent or erect, 0.1–0.8(–1) cm, thinly tomentose.

Involucres

appressed to branches, cylindric-turbinate, 3–4 × 2–2.5 mm, glabrous;

teeth 5, erect, 0.2–0.3 mm.

1 per node, campanulate, 3–4.5 × 2.5–3.5 mm wide, thinly tomentose to subglabrous;

teeth 5, erect, 0.5–1.2 mm.

Flowers

1.5–2 mm;

perianth white to pink or red, rarely yellow, glabrous;

tepals monomorphic, oblong-obovate;

stamens included, 1–1.5 mm;

filaments pilose proximally.

3.5–4.5(–5) mm;

perianth white, glabrous;

tepals connate proximal 1/3, dimorphic, those of outer whorl broadly cordate, 2–3 mm wide, apex rounded, those of inner whorl oblanceolate, 1–2 mm wide;

stamens exserted, 3.5–4.5 mm;

filaments pilose proximally.

Achenes

brown, 3-gonous, 2 mm.

light brown, 4–4.5 mm, glabrous.

2n

= 40.

Eriogonum davidsonii

Eriogonum terrenatum

Phenology Flowering May–Sep. Flowering Aug–Nov.
Habitat Sandy to gravelly flats and slopes, mixed grassland, saltbush, chaparral, and sagebrush communities, oak and montane conifer woodlands Clayey slopes and flat, creosote bush communities
Elevation (400-)900-2600 m ((1300-)3000-8500 ft) 1000-1200 m (3300-3900 ft)
Distribution
from FNA
AZ; CA; NV; UT; Mexico (Baja California)
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ
[BONAP county map]
Discussion

Eriogonum davidsonii is widespread and mostly common to occasionally abundant or weedy in Arizona, California, southern Nevada, and southern Utah. It is exceedingly variable. In the northern part of California, its range approaches that of E. luteolum var. luteolum, and the two can be difficult to differentiate. To the south, in Tulare County, the distinction between E. davidsonii and E. luteolum var. pedunculatum also is difficult. Specimens of Eriogonum davidsonii with curved inflorescence branches resemble E. cithariforme in the mountains of southern California, and care must be taken to separate E. davidsonii from its more robust relative, E. molestum in the San Jacinto Mountains of Riverside County. The disjunct populations in Utah and Arizona are somewhat different in appearance but presently do not seem worthy of taxonomic separation. The epithet juncinellum is available should recognition be desired.

Seeds of Davidson’s wild buckwheat were pounded into a meal and eaten dry by the Kawaiisu people of southern California (M. L. Zigmond 1981).

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

Eriogonum terrenatum is confined to two geographically separate areas. Near Vail, Pima County, it is restricted to clayey outcrops of the Pantano Formation, whereas near Fairbanks, Cochise County, it is confined to the eroded, clay slopes and flats of the Saint David Formation.

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

Source FNA vol. 5, p. 422. FNA vol. 5, p. 254.
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. 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. 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. sphaerocephalum, E. strictum, E. subreniforme, E. suffruticosum, E. temblorense, E. tenellum, E. ternatum, 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
Synonyms E. molestum var. davidsonii, E. vimineum var. davidsonii, E. vimineum var. glabrum, E. vimineum subsp. juncinellum
Name authority Greene: Pittonia 2: 295. (1892) Reveal: Phytologia 86: 144. (2004)
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