Flora of North America species comparison

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Eriogonum heermannii

Eriogonum crosbyae

Heerman buckwheat, Heermann's buckwheat, Heermann's wild buckwheat

Crosby's buckwheat, Crosby's wild buckwheat
Habit Shrubs and subshrubs, spreading to rounded and occasionally erect, not scapose, (0.5–)1–20 × 2–25 dm, glabrous or occasionally floccose, sometimes scabrellous, greenish, infrequently grayish. Herbs, matted, scapose, 0.05–1.5(–2) × (0.1–)1–3 dm, floccose to tomentose or glabrous, sometimes glandular, greenish or grayish.
Stems

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 to stout, solid, not fistulose, 0.02–0.5 dm, thinly tomentose or glabrous.

matted, with persistent leaf bases, up to 1/5 height of plant;

caudex stems matted;

aerial flowering stems scapelike, weakly erect to erect, slender, solid, not fistulose, 0.02–1.5(–1.8) dm, floccose to tomentose or glabrous, occasionally also or only sparsely to densely glandular.
Leaves

cauline, 1 per node, quickly deciduous;

petiole 0.1–1.5 cm, floccose or glabrous;

blade linear, oblanceolate or spatulate or elliptic, or oblong, (0.4–)1–2(–4) × 0.1–0.8 cm, tomentose to floccose or glabrous abaxially, floccose to thinly floccose or glabrous adaxially, margins plane.

basal, fasciculate in terminal tufts;

petiole 0.2–3(–3.5) cm, tomentose, infrequently glandular;

blade oblanceolate to spatulate or elliptic to obovate or ovate, (0.5–)1–2(–3) × 0.2–1(–1.5) cm, densely white- or grayish-tomentose on both surfaces, sometimes less and greenish white adaxially, margins plane.
Inflorescences

cymose or racemose, 1–25(–30) × 1–30(–35) cm;

branches dichotomous, sometimes with secondaries suppressed, smooth or angled to ridged and grooved, glabrous or occasionally floccose or scabrous;

bracts 3, scalelike, 0.3–2 mm.

capitate, 0.7–1.5 cm;

branches absent;

bracts 3, narrowly triangular to triangular, scalelike, 1–3 mm.
Peduncles

absent.

absent.
Involucres

1 per node, narrowly turbinate or campanulate, 0.7–3 × 0.7–4 mm, glabrous, infrequently floccose;

teeth 5, erect, 0.3–0.7 mm.

(3–)5–8 per cluster, turbinate to campanulate, (1.5–)2–5(–5.5) × 2–4(–4.5) mm, rigid or membranous, tomentose to floccose, occasionally glabrous except for floccose teeth, rarely sparsely pilose and glandular;

teeth 5–7, erect to spreading or reflexed, 0.5–1.5 mm.
Flowers

(1.5–)2–4 mm;

perianth white, yellowish white, pink, or reddish, glabrous;

tepals connate proximal 1/4, dimorphic, those of outer whorl obovate to orbiculate, those of inner whorl narrowly lanceolate to oblong;

stamens exserted, 2–5 mm;

filaments pilose proximally.

1.5–3.5(–4) mm, glabrous or occasionally minutely glandular, pustulose in some;

perianth yellow to pale yellow or, rarely, cream;

tepals connate proximal 1/4–1/3, monomorphic, oblong to oblong-obovate;

stamens exserted, 1.5–4 mm;

filaments glabrous or sparsely pilose proximally.
Achenes

light brown to brown, 2–5 mm, glabrous.

light brown, 2–4 mm, glabrous or sometimes with minute bristles on beak.
2n

= 40.

Eriogonum heermannii

Eriogonum crosbyae
Phenology Flowering May–Aug.
Habitat White tuffaceous shale volcanic outcrops, metamorphic rock outcrops, or basaltic or granitic sandy flats, washes, slopes, and ridges, saltbush and sagebrush or high-elevation sagebrush to alpine tundra communities, juniper or montane conifer woodlands
Elevation (1200-)1400-3100
Distribution
from FNA
AZ; CA; NV; UT
[WildflowerSearch map]
[BONAP county map]
from FNA
ID; MT; NV; OR
[WildflowerSearch map]
[BONAP county map]
Discussion

Varieties 8 (8 in the flora).

As Eriogonum heermannii is here circumscribed, the number of varieties is dramatically decreased from past presentations, with E. apachense reduced to synonymy under a now greatly expanded var. argense. Also included in that variety is the more stoutly branched var. subracemosum. The southern var. heermannii of basically desert ranges and the more northern var. occidentale of the Coast Ranges in California are maintained, but their separation is more traditional than certain. The fragile and bulky nature of many dried, often poorly prepared specimens, and the tendency for leaves to fall away have made varietal identification within E. heermannii difficult.

Eriogonum heermannii varieties are food plants for Ellis’s dotted-blue butterfly (Euphilotes ellisi) and the Mormon metalmark (Apodemia mormo mormo).

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

Eriogonum crosbyae, as now defined, is widely scattered in the valley bottoms and foothills, and atop several mountain ranges of central Idaho (Blaine, Butte, Camas, Custer, and Lemhi counties) and in western Montana (Deer Lodge and Ravalli counties). It is disjunct to southwestern Idaho (Owyhee Mountains, Owyhee County), southeastern Oregon (Guano and Coleman valleys, Harney County, and Fish Fin Rim, Lake County), and in northwestern Nevada (Washoe and Humboldt counties south through Douglas, Lyon, and Pershing counties to Mineral County). It also occus in the Marys River Peak area of Elko County, Nevada.

The species may be subdivided into four phases, for which names are available. The vast majority of populations have bright yellow flowers with pustulose bases and midveins. The pustulose condition may also be observed in Eriogonum chrysops (on pale greenish-yellow flowers) and in E. mancum (with cream-colored flowers). Populations with pale yellow flowers here assigned to E. crosbyae occur in the mountains near Mackay, Idaho, and cream-colored flowers are found near Challis and around Salmon, both well outside the known ranges of E. chrysops and E. mancum. Final resolution of the taxonomy of this group awaits further study.

(Discussion copyrighted by Flora of North America; reprinted with permission.)
Key
1. Flowering stems and inflorescence branches round or angled, scabrellous or papillate-scabrous; plants often densely branched
→ 2
1. Flowering stems and inflorescence branches round, not angled, usually smooth, glabrous or thinly tomentose; plants sparsely branched
→ 3
2. Flowering stems and inflorescence branches round, usually distinctly scabrellous or infrequently papillate-scabrous; Arizona, se California, Nevada
var. argense
2. Flowering stems and inflorescence branches sharply ridged and deeply grooved, minutely scabrellous; nw Arizona, se California, s Nevada, sw Utah
var. sulcatum
3. Involucres not racemosely arranged on inflorescence branches, or only last 2-3 so disposed; inflorescences diffusely branched, glabrous; Great Basin or northeast edge of Mojave Desert
→ 4
3. Involucres racemosely arranged along inflorescence branches or at least at tips of branches; inflorescences openly branched, glabrous or floccose to thinly tomentose; Mojave and Sonoran deserts
→ 5
4. Inflorescence branches mostly slender, smooth, not ridged, not spinose; inflorescences 3-15(-23) × 5-20 cm; subshrubs or shrubs, 3-7 × 5-12(-15) dm; Great Basin, ec California and Nevada
var. humilius
4. Inflorescence branches stoutish, faintly ridged and grooved, spinose; inflorescences 3-7(-10) × 3-10(-12) cm; shrubs, 1-3 × 1.5-5(-8) dm; Mojave Desert, sw Utah and nw Arizona
var. subspinosum
5. Inflorescence branches thinly tomentose to floccose; s California, s Nevada, nw Arizona
var. floccosum
5. Inflorescence branches glabrous; s Nevada, California
→ 6
6. Involucres racemosely arranged; inflorescence branches whiplike; s Nevada
var. clokeyi
6. Involucres racemosely arranged only distally; inflorescence branches not whiplike; California
→ 7
7. Leaf blades 0.5-1.5 cm, glabrous abaxially; inflorescence branches stout; sc California
var. heermannii
7. Leaf blades 1.5-3(-4) cm, mostly tomentose to floccose abaxially (at least in early anthesis); inflorescence branches slender; sw California
var. occidentale
Source FNA vol. 5, p. 304. FNA vol. 5, p. 277.
Parent taxa Polygonaceae > subfam. Eriogonoideae > Eriogonum > subg. Eucycla 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. 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. 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. 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. heermannii var. argense, E. heermannii var. clokeyi, E. heermannii var. floccosum, E. heermannii var. heermannii, E. heermannii var. humilius, E. heermannii var. occidentale, E. heermannii var. subspinosum, E. heermannii var. sulcatum
Synonyms E. geniculatum E. capistratum, E. capistratum var. muhlickii, E. capistratum var. welshii, E. meledonum, E. ochrocephalum var. alexanderae, E. verrucosum
Name authority Durand & Hilgard: in War Department [U.S.], Pacif. Railr. Rep. 5(3): 14. (1857) Reveal: Brittonia 33: 442, fig. 1. (1981)
Web links 
Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).



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