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

Gordon's buckwheat, Gordon's eriogonum, Gordon's wild buckwheat

San Pedro River wild buckwheat

Habit Herbs, erect to spreading, annual, (0.5–)1–5(–7) dm, glabrous or sparsely hispid, grayish. Shrubs, sprawling to erect, not scapose, 1–4(–5) × (1–)2–6(–9) dm, thinly tomentose or floccose to subglabrous, greenish.
Stems

caudex absent;

aerial flowering stems erect, solid, not fistulose, 0.5–1.5(–3) dm, glabrous or sparsely hispid.

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, glabrous or sparsely hirsute;

blade obovate to round or reniform, 1–5 × 1–5 cm, sparsely villous to hirsute and green on both surfaces, becoming glabrous with age, margins plane.

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, open to dense, 5–40(–50) × 5–50 cm;

branches not fistulose, glabrous or sparsely hispid;

bracts 3, scalelike, 0.5–2(–3) × 0.5–2.5 mm.

cymose, compact, 1–3 × 1–3 cm;

branches dichotomous, thinly tomentose;

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

Peduncles

erect, straight, slender, 0.5–2.5(–4) cm, glabrous.

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

Involucres

campanulate, 0.6–1.5 × 0.8–1.5 mm, glabrous;

teeth 5, erect, 0.2–0.4 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

1–2.5 mm;

perianth white with greenish or reddish midribs, rarely yellowish, becoming pink to rose, glabrous;

tepals monomorphic, oblong to narrowly ovate;

stamens included to exserted, 1–1.8 mm;

filaments glabrous.

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

shiny light brown to brown, 3-gonous, 2–2.5 mm, glabrous.

light brown, 4–4.5 mm, glabrous.

Eriogonum gordonii

Eriogonum terrenatum

Phenology Flowering May–Oct. Flowering Aug–Nov.
Habitat Sandy to clayey flats and slopes, saltbush, greasewood, and sagebrush communities, pinyon and/or juniper or montane conifer woodlands Clayey slopes and flat, creosote bush communities
Elevation 900-2200 m (3000-7200 ft) 1000-1200 m (3300-3900 ft)
Distribution
from FNA
AZ; CO; NE; NM; SD; UT; WY
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ
[BONAP county map]
Discussion

Eriogonum gordonii is common to even locally abundant throughout a range that extends in an arc from the Colorado Plateau of extreme northern Coconino and Apache counties, Arizona, and San Juan County, New Mexico, northward through the desert regions of eastern Utah and western Colorado into southwestern Wyoming, then northeastward mainly in short-grass prairie through east-central Wyoming and extreme northwestern Nebraska to South Dakota. A series of disjunct populations occurs in Fremont and Las Animas counties in Colorado. The species can be weedy in appearance but usually is absent from areas of significant disturbance, unlike other annual wild buckwheats.

(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. 391. FNA vol. 5, p. 254.
Parent taxa Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Ganysma 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. 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
Name authority Bentham: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 14: 20. (1856) Reveal: Phytologia 86: 144. (2004)
Web links