[The Genus Eriogonum in the Columbia River Gorge of Oregon and Washington]

Rock Buckwheat, Round-headed Buckwheat

Eriogonum sphaerocephalum

Rock Buckwheat, Round-headed Buckwheat Eriogonum sphaerocephalum var. sphaerocephalum (Synonyms: Eriogonum faciculifolium, Eriogonum geniculatum, Eriogonum sphaerocephalum var. geniculatum)


Characteristics:

The rock buckwheat is a large, shrubby perennial plant from 5-40 cm high. The leaves are oblanceolate to linear-spatulate or even linear and are found at the tips of the stems. The leaves are gray woolly below The leaves tend to be more woolly hairy below than above. Long flower stems are leafless except for a whorl of wide spatulate leaves directly at the point where the flower stem branches to give rise to the 2 or 3 round heads of flowers. Shorter flower stems may appear very leafy as it may be difficult to distinguish where the flower stem arises from the leafy stem. (See photos.)The inflorescence often consists of two umbellate clusters of flowers at the tips of the stems. The involucres are bell-shaped to broadly tubular with 6-10 oblong lobes about 3 mm long and about equal in length to the tube. The flowers are yellow, often white or pinkish, in round clusters atop an umbel.


Similar Species:

Wyeth Buckwheat: Eriogonum heracloides -

Sulfurflower: Eriogonum umbellatum -

Piper's Buckwheat: Eriogonum flavum -


Habitat:

Rockbuckwheat is found amongst sagebrush and juniper in the lowlands to the ponderosa forest at moderate elevations.


Range:

Rock buckwheat may be found from north-central Washington south along the east Cascade slope to northeastern California, and east to western Idaho and Nevada. In the Columbia River Gorge, rock buckwheat can be found on dry, rocky slopes and flats from near the mouth of Rock Creek east past Roosevelt, WA.


Rock Buckwheat, Round-headed Buckwheat Eriogonum sphaerocephalum var. sphaerocephalum (Synonyms: Eriogonum faciculifolium, Eriogonum geniculatum, Eriogonum sphaerocephalum var. geniculatum)

Rock buckwheat as seen as part of a planting at the Mark O. Hatfield West Trailhead about one mile east of Hood River, Oregon.........May 14, 2013. This species is not native to this portion of the Columbia River Gorge.

Ventral leaf surfaces of Rock Buckwheat, Round-headed Buckwheat Eriogonum sphaerocephalum var. sphaerocephalum (Synonyms: Eriogonum faciculifolium, Eriogonum geniculatum, Eriogonum sphaerocephalum var. geniculatum) - Rock Buckwheat, Round-headed Buckwheat Eriogonum sphaerocephalum var. sphaerocephalum (Synonyms: Eriogonum faciculifolium, Eriogonum geniculatum, Eriogonum sphaerocephalum var. geniculatum)

The photos above show close-ups of the lower (left) and upper (right) surfaces of the leaf blades of rock buckwheat as seen on the eastbank of the Columbia River near Vantage, WA.........June 22, 2006. Note how the lower surface is more densely haired with whitish hairs than the upper surface. Note also the inrolled margins to the blades, especially on the younger leaves at left.


Rock Buckwheat, Round-headed Buckwheat Eriogonum sphaerocephalum var. sphaerocephalum (Synonyms: Eriogonum faciculifolium, Eriogonum geniculatum, Eriogonum sphaerocephalum var. geniculatum)
The photo above shows rock buckwheat as seen along Washington Highway 14 at Roosevelt, WA........June 2, 2008.

Habitat of Rock Buckwheat, Round-headed Buckwheat Eriogonum sphaerocephalum var. sphaerocephalum (Synonyms: Eriogonum faciculifolium, Eriogonum geniculatum, Eriogonum sphaerocephalum var. geniculatum) - Leaves of Rock Buckwheat: Eriogonum sphaerocephalum - Inflorescence of Rock Buckwheat, Round-headed Buckwheat Eriogonum sphaerocephalum var. sphaerocephalum (Synonyms: Eriogonum faciculifolium, Eriogonum geniculatum, Eriogonum sphaerocephalum var. geniculatum) - Inflorescence of Rock Buckwheat, Round-headed Buckwheat Eriogonum sphaerocephalum var. sphaerocephalum (Synonyms: Eriogonum faciculifolium, Eriogonum geniculatum, Eriogonum sphaerocephalum var. geniculatum)

The photos above show several views of rock buckwheat as seen along Washington Highway #14 at Roosevelt, WA.......June 2, 2008. Click each picture to see an enlarged version of each.


Paul Slichter