Burke: Eriogonum thymoides vs. Eriogonum sphaerocephalum

	Eriogonum thymoides	Eriogonum sphaerocephalum
	thyme buckwheat, thyme-leaf wild buckwheat	rock buckwheat, round-headed eriogonum
Habit	Intricately branched, low and spreading to erect shrub 5-15 cm. tall, somewhat gray-woolly to silky throughout.	Spreading to erect sub-shrub, freely branched, forming a dense, rounded clump to 4 dm. tall.
Leaves	Leaves many, linear to linear-spatulate, 3-10 mm. long, usually revolute, somewhat wooly beneath and silky above.	Numerous in whorls at the branch tips, broadly linear, 1-3 cm. long by 3-6 mm. wide, somewhat grayish-woolly on the underside and less so on the top
Flowers	Flowering stems 3-8 cm. tall, always with a whorl of leaves about mid-length; involucres single and terminal, top-shaped, 3-5 mm. long, the teeth 6-8, erect, triangular, 1 mm. long; perianth with a stipitate base 0.5-1 mm. long, densely hairy, the 6 segments obovate, yellow or white to rose-red, 4-6 mm. long; plants dioecious, the staminate flowers with 9 stamens, the filaments hairs only at the base, the pistillate flowers with stout, spreading styles 0.5-1 mm. long.	Flowering stems 5-10 cm. tall, terminating in an umbel of two or more pedicels, which are subtended by several leafy bracts; the involucres are cup-shaped, with 6-10 oblong lobes about 3 mm. long, about equaling the tube, reflexed to spreading; the tepals are usually yellow, but occasionally white or pinkish, 6-8 mm. long with a stipe-like base, and forming a ball-like flower cluster.
Fruits	Achenes pubescent above

	Eriogonum thymoides	Eriogonum sphaerocephalum
Identification notes	Separate from the similar Eriogonum douglasii by the involucre lobes; E. thymoides has erect lobes, E. douglasii, reflexed to spreading lobes.	The dense, rounded clump of fine branches covered with bright yellow spheres of flowers should identify this species.
Flowering time	April-June	May-July
Habitat	Sagebrush deserts, dry ponderosa pine forest openings, and open ridges in lower mountains.	Sagebrush or juniper flats to ponderosa pine forests at low elevations.
Distribution	Occurring east of the Cascades crest in central Washington; central Washington to Oregon, east to Idaho. [WildflowerSearch map] [BONAP county map]	Occurring east of the Cascades crest in Washington; Washington to California, east to Idaho and Nevada. [WildflowerSearch map] [BONAP county map]
Origin	Native	Native
Conservation status	Not of concern	Not of concern
Sibling taxa	E. baileyi, E. cernuum, E. codium, E. compositum, E. douglasii, E. elatum, E. flavum, E. heracleoides, E. maculatum, E. marifolium, E. microtheca, E. niveum, E. nudum, E. ovalifolium, E. pyrolifolium, E. sphaerocephalum, E. strictum, E. umbellatum, E. vimineum	E. baileyi, E. cernuum, E. codium, E. compositum, E. douglasii, E. elatum, E. flavum, E. heracleoides, E. maculatum, E. marifolium, E. microtheca, E. niveum, E. nudum, E. ovalifolium, E. pyrolifolium, E. strictum, E. thymoides, E. umbellatum, E. vimineum
Subordinate taxa		E. sphaerocephalum var. halimioides, E. sphaerocephalum var. sphaerocephalum, E. sphaerocephalum var. sublineare
Web links	Local floras: OR, WA Local Web sites: Flora NW, PNW Herbaria, Turner Photog. WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria, Turner Photog. WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Eriogonum sphaerocephalum

thyme buckwheat, thyme-leaf wild buckwheat

rock buckwheat, round-headed eriogonum

Habit

Intricately branched, low and spreading to erect shrub 5-15 cm. tall, somewhat gray-woolly to silky throughout.

Spreading to erect sub-shrub, freely branched, forming a dense, rounded clump to 4 dm. tall.

Leaves

Leaves many, linear to linear-spatulate, 3-10 mm. long, usually revolute, somewhat wooly beneath and silky above.

Numerous in whorls at the branch tips, broadly linear, 1-3 cm. long by 3-6 mm. wide, somewhat grayish-woolly on the underside and less so on the top

Flowers

Flowering stems 3-8 cm. tall, always with a whorl of leaves about mid-length;

involucres single and terminal, top-shaped, 3-5 mm. long, the teeth 6-8, erect, triangular, 1 mm. long;

perianth with a stipitate base 0.5-1 mm. long, densely hairy, the 6 segments obovate, yellow or white to rose-red, 4-6 mm. long; plants dioecious, the staminate flowers with 9 stamens, the filaments hairs only at the base, the pistillate flowers with stout, spreading styles 0.5-1 mm. long.

Flowering stems 5-10 cm. tall, terminating in an umbel of two or more pedicels, which are subtended by several leafy bracts; the involucres are cup-shaped, with 6-10 oblong lobes about 3 mm. long, about equaling the tube, reflexed to spreading; the tepals are usually yellow, but occasionally white or pinkish, 6-8 mm. long with a stipe-like base, and forming a ball-like flower cluster.

Fruits

Achenes pubescent above