Eriophyllum lanatum, with the common names common woolly sunflower, Oregon sunshine and golden yarrow, is a common, widespread, North American plant in the family Asteraceae. Description Eriophyllum lanatum is a perennial herb growing from in height, in well-branched clumps. Both the stems and leaves may be covered with a woolly gray hair, but some plants lack this. The leaves are long, linear on the upper stems, and slender and pinnately lobed on the lower stems. The hairs conserve water by reflecting heat and reducing air movement across the leaf's surface. The flowers are yellow and composite, looking much like true sunflowers, and sometimes grow to about wide. Both the (8–12) ray and disk flowers are yellow, with one flower head on each flowering stalk. The flower heads have 6–14 rays, which are darker towards the base, and several disk flowers. They bloom from May to August. The seeds have scales at the tip. Taxonomy The Lewis and Clark Expedition reportedly saw this plant growing above their camp on the Clearwater River (near present-day Kamiah, Idaho), and collected two specimens on 6 June 1806. Botanist Frederick Traugott Pursh studied the plants collected on the expedition; his first classification and naming of the species, as Actinella lanata, was published in 1813. The common name "woolly sunflower" is often used to describe any member of the genus Eriophyllum. Varieties Varieties include: Eriophyllum lanatum var. achillioides (DC.) Jeps. — California, Nevada, Oregon. Eriophyllum lanatum var. arachnoideum (Fisch. & Avé-Lall.) Jeps. — Spiderweb sunflower; endemic to the California Coast Ranges from Del Norte County to Monterey County in California. Eriophyllum lanatum var. croceum (Greene) Jeps. — Sierra woolly sunflower; endemic to the Sierra Nevada in California. Eriophyllum lanatum var. grandiflorum (A.Gray) Jeps. — Large flowered woolly sunflower; northern California, Oregon. Eriophyllum lanatum var. hallii Constance — Fort Tejon woolly sunflower, Hall's woolly sunflower; endemic to the Tehachapi Mountains in Kern County, and Sierra Madre Mountains in Santa Barbara County, in southern California. Eriophyllum lanatum var. integrifolium (Hook.) Smiley — Oregon sunshine; California, Idaho, Montana, Nevada, Oregon, Utah, Washington, Wyoming. Eriophyllum lanatum var. lanatum — Idaho, Montana, Oregon, Washington. Eriophyllum lanatum var. lanceolatum (Howell) Jeps. — endemic to the Klamath Mountains, in NW California and SW Oregon. Eriophyllum lanatum var. leucophyllum (DC.) W.R.Carter — British Columbia, Oregon, Washington. Eriophyllum lanatum var. obovatum (Greene) H.M.Hall — Southern Sierra woolly sunflower; endemic to the western Sierra Nevada and