Eriogonum

Eriogonum is a genus of flowering plants in the family Polygonaceae. The genus is found in North America and is known as wild buckwheat. This is a highly species-rich genus, and indications are that active speciation is continuing. It includes some common wildflowers, such as the California buckwheat.
The genus derived its name from the Greek word erion meaning 'wool' and gonu meaning 'knee or joint'. The author of the genus, Michaux, explained the name as describing the first named species of the genus as a wooly plant with sharply bent stems. Despite sharing the common name "buckwheat", Eriogonum is part of a different genus from the cultivated European buckwheat and than other plant species also called wild buckwheat.
In addition to the widespread common species, approximately a third of the species in the genus are rare, endangered, or threatened. One such species came into the news in 2005 when the Mount Diablo buckwheat was rediscovered.

Ecology

Eriogonum species are used as food plants by the larvae of some Lepidoptera. An example of a butterfly that uses this plant for food is the Lycaena heteronea. Several of these are monophagous, meaning their caterpillars only feed on this genus, sometimes just on a single taxon of Eriogonum. Wild buckwheat flowers are also an important source of food for these and other Lepidoptera. In some cases, the relationship is so close that Eriogonum and dependent Lepidoptera are in danger of coextinction.
Monophagous Lepidoptera on wild buckwheat include:Apodemia mormo – feeds exclusively on Eriogonum

* Apodemia mormo langei – only known from Eriogonum nudum ssp. auriculatumChionodes dammersi – feeds exclusively on EriogonumChionodes luteogeminatus – only known from Eriogonum niveumEuphilotes enoptes smithi – only known from Eriogonum latifolium and Eriogonum parvifoliumEuphilotes battoides allyni - only known from Eriogonum parvifolium

Additionally, bees of the sagebrush steppe rely on the nectar of desert buckwheats, and birds and rodents eat the seeds.

Uses

Some varieties of eriogonum, such as California buckwheat were and still are used as medicinal and food crops by Native American tribes.

Selected species

image:Eriogonum hirtellum 2.jpg|thumb|right|Eriogonum hirtellum
image:Eriogonum ursinum 3.jpg|thumb|right|Talus buckwheat
Eriogonum ursinum
image:Eriogonum wrightii var subscaposum 1.jpg|thumb|right|Eriogonum wrightii var. subscaposumEriogonum abertianum – Abert's buckwheatEriogonum alatum – winged buckwheatEriogonum alexanderaeEriogonum aliquantum – Cimarron buckwheatEriogonum alpinum – trinity buckwheatEriogonum ampullaceum – mono buckwheatEriogonum androsaceum – rock-jasmine buckwheatEriogonum angulosum – anglestem buckwheatEriogonum apiculatum – San Jacinto buckwheatEriogonum apricum – Ione buckwheatEriogonum arborescens – Santa Cruz Island buckwheatEriogonum argillosum – clay buckwheatEriogonum argophyllum – Sulphur Hot Springs buckwheat, Ruby Valley buckwheatEriogonum baileyi – Bailey's buckwheatEriogonum bicolor – Pretty buckwheatEriogonum brachyanthum – shortflower buckwheatEriogonum brachypodum – Parry's buckwheatEriogonum brandegeei – Brandegee's buckwheatEriogonum breedlovei – Paiute buckwheatEriogonum brevicaule – shortstem buckwheatEriogonum butterworthianum – Butterworth's buckwheatEriogonum caespitosum – matted buckwheatEriogonum calcareumEriogonum callistum – Tehachapi buckwheatEriogonum cedrorum – The Cedars buckwheatEriogonum cernuum – nodding buckwheatEriogonum cinereum – ashyleaf buckwheat, coastal buckwheatEriogonum cithariforme – Cithara buckwheatEriogonum codium – basalt desert buckwheatEriogonum coloradense – Colorado buckwheatEriogonum compositum – arrowleaf buckwheatEriogonum congdonii – Congdon's buckwheatEriogonum contiguum – Reveal's buckwheatEriogonum corymbosum – crispleaf buckwheat

* Eriogonum corymbosum var. nilesii – Nile's wild buckwheat, Las Vegas buckwheatEriogonum covilleanum – Coville's buckwheatEriogonum crocatum – conejo buckwheat or saffron buckwheatEriogonum crosbyae – Crosby's buckwheatEriogonum cusickii – Cusick's buckwheatEriogonum dasyanthemum – chaparral buckwheatEriogonum davidsonii – Davidson's buckwheatEriogonum deflexum – flatcrown buckwheatEriogonum deserticola – Colorado Desert buckwheatEriogonum diatomaceum – Churchill Narrows buckwheatEriogonum diclinum – Jaynes Canyon buckwheatEriogonum domitumEriogonum douglasii – Douglas buckwheatEriogonum elatum – tall woolly buckwheatEriogonum encelioides – Encelia buckwheatEriogonum eremicola – Telescope Peak buckwheatEriogonum evanidum – vanishing wild buckwheatEriogonum exilifolium – dropleaf buckwheatEriogonum fasciculatum – California buckwheatEriogonum flavum – yellow buckwheatEriogonum giganteum – Saint Catherine's lace
* Eriogonum giganteum var. compactum – Santa Barbara Island buckwheatEriogonum gilmanii – Gilman's buckwheatEriogonum gossypinum – cottony buckwheatEriogonum gracile – slender woolly buckwheatEriogonum gracilipes – White Mountain buckwheat, raspberry buckwheatEriogonum gracillimum – rose and white buckwheatEriogonum grande – redflower buckwheatEriogonum gypsophilum – gypsum wild buckwheatEriogonum heermannii – Heermann's buckwheatEriogonum helichrysoides – Strawflower wild buckwheatEriogonum heracleoides – parsnip-flower BuckwheatEriogonum hirtellum – Klamath Mountain BuckwheatEriogonum hoffmannii – Hoffmann's buckwheatEriogonum hookeri – Hooker's buckwheatEriogonum incanum – frosted buckwheatEriogonum inflatum – desert trumpet, bladderstem, Indian pipe-weedEriogonum intrafractum – napkinring, jointed buckwheatEriogonum jamesii – James' buckwheatEriogonum kelloggii – red mountain buckwheatEriogonum kennedyi – Kennedy's buckwheatEriogonum latens – Inyo buckwheatEriogonum latifolium – seaside buckwheatEriogonum libertini – Dubakella Mountain buckwheatEriogonum lobbii – Lobb's buckwheatEriogonum longifolium – longleaf buckwheat
* Eriogonum longifolium var. harperi – Harper's umbrella plant or Harper's buckwheat
* Eriogonum longifolium var. gnaphalifolium – scrub buckwheat or long-leaf wild Buckwheat
* Eriogonum longifolium var. longifolium – longleaf buckwheat
* Eriogonum longifolium var. lindheimeri – Lindheimer's long-leaf Eriogonum or Lindheimer's buckwheatEriogonum luteolum – goldencarpet buckwheatEriogonum maculatum – spotted buckwheatEriogonum marifolium – marumleaf buckwheatEriogonum microthecum – slender buckwheatEriogonum mohavense – Western Mojave buckwheatEriogonum molestum – pineland buckwheatEriogonum nervulosum – Snow Mountain buckwheatEriogonum nidularium – birdnest buckwheatEriogonum niveum – snow buckwheatEriogonum nortonii – pinnacles buckwheatEriogonum nudum – naked buckwheat
* Eriogonum nudum ssp. auriculatumEriogonum nummulare – Kearney buckwheat, money buckwheatEriogonum ochrocephalum – whitewoolly buckwheatEriogonum ovalifolium – cushion buckwheat, oval-leaf buckwheatEriogonum palmerianum – Palmer's buckwheatEriogonum panamintense – Panamint Mountain buckwheatEriogonum parishii – mountainmistEriogonum parvifolium – coast buckwheat, dune buckwheat or cliff buckwheatEriogonum pauciflorum – Fewflower buckwheatEriogonum pelinophilum – clay-loving wild buckwheatEriogonum pendulum – waldo buckwheatEriogonum plumatella – yucca buckwheatEriogonum prattenianum – Nevada City buckwheatEriogonum prociduum – prostrate buckwheatEriogonum pusillum – yellowturbansEriogonum pyrolifolium – pyrola-leaved buckwheatEriogonum reniforme – kidneyleaf buckwheatEriogonum rixfordii – pagoda buckwheatEriogonum rosense – rosy buckwheat, mountain rose buckwheat
* Eriogonum rosense var. beatleyae – Beatley's buckwheatEriogonum roseum – wand buckwheatEriogonum salicornioides – glasswort buckwheatEriogonum saxatile – hoary buckwheatEriogonum shockleyi – cowpie buckwheatEriogonum siskiyouense – Siskiyou buckwheatEriogonum soredium – Frisco buckwheatEriogonum spectabile – Barron's buckwheatEriogonum spergulinum – spurry buckwheatEriogonum sphaerocephalum – rock buckwheatEriogonum strictum – blue mountain buckwheatEriogonum ternatum – ternate buckwheatEriogonum tiehmii – Tiehm's buckwheatEriogonum thomasii – Thomas' buckwheatEriogonum thurberi – Thurber's buckwheatEriogonum thymoides – thymeleaf buckwheatEriogonum tomentosum – dogtongue wild buckwheatEriogonum trichopes – little desert trumpetEriogonum tripodum – tripod buckwheatEriogonum truncatum – Mount Diablo buckwheatEriogonum umbellatum – sulphurflower buckwheatEriogonum ursinum – talus buckwheat, Bear Valley buckwheatEriogonum vimineum – wickerstem buckwheatEriogonum viridescens – twotooth buckwheatEriogonum visheri – Dakota wild buckwheat, Visher's buckwheatEriogonum wrightii – bastardsageEriogonum zapatoenseEriogonum zionis – Zion buckwheat