[Buckwheats: The Genus Eriogonum East of the Cascade Mountains of Oregon and Washington]

Rock Buckwheat, Halimium Wild Buckwheat

Eriogonum sphaerocephalum var. halimioides

Synonyms: Eriogonum fruticulosum, Eriogonum halimioides

The photo above shows a single, umbellate flower head of rock buckwheat (var. halimioides) as seen on steep slopes above the John Day River along Oregon Highway 19 at milepost 80 in central Oregon..........May 28, 2007.

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.

Varieties of Eriogonum sphaerocephalum:

var. halimioides - Flowers pale yellow to cream or a faint dingy yellow. Inflorescence capitate or umbellate. Leaf blades usually narrowly oblanceolate to narrowly spatulate with non-revolute margins.

var. sphaerocephalum - Flowers bright yellow. Inflorescence umbellate to compound-umbellate. Leaf blades oblanceolate with non-revolute margins (not rolled under).

var. sublineare - Flowers pale yellow to cream or a faint dingy yellow. Inflorescence capitate or umbellate. Leaf blades usually linear-oblanceolate with revolute (rolled under) margins.

Similar Species:

Douglas' Buckwheat: Eriogonum douglasii - Similar to variety sublineare.

Piper's Buckwheat: Eriogonum flavum -

Wyeth Buckwheat: Eriogonum heracloides -

Sulfurflower: Eriogonum umbellatum -

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.

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The photos above show various views of rock buckwheat (var. halimioides) as seen on steep slopes above the John Day River along Oregon Highway 19 at milepost 80 in central Oregon..........May 28, 2007.

The photo above shows a close-up of the inflorescence of rock buckwheat as seen on arid flats to the south of Winter Ridge in the Fremont NF..........July 19, 1998. Note that the flowers are more whitish than those of var. sphaerocephalum. Note also the pubescence on the outside of the perianth.

Rock Buckwheat, Halimium Wild Buckwheat: Eriogonum sphaerocephalum var. halimioides (Synonyms: Eriogonum fruticulosum, Eriogonum halimioides)

The photo above shows Eriogonum sphaerocephalum var. halimioides as seen on arid flats to the south of Winter Ridge in the Fremont NF.........July 19, 1998.

Rock Buckwheat, Halimium Wild Buckwheat: Eriogonum sphaerocephalum var. halimioides (Synonyms: Eriogonum fruticulosum, Eriogonum halimioides)

Photo above of Eriogonum sphaerocephalum var. halimioides from a roadside on Manastash Ridge (central Washington).....June 22, 1997.

Paul Slichter