Eriophyllum lanatum var. arachnoideum (Fisch. & Ave-Lall.) Jepson

Eriophyllum lanatum, with the common names common woolly sunflower, Oregon sunshine and golden yarrow,^[3] is a common, widespread, North American plant in the family Asteraceae.^[4][5][2]

Description

Eriophyllum lanatum is a perennial herb growing from 30 to 60 centimetres (12 to 24 inches) 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 2.5–7.5 cm (1–3 in) long,^[3] linear on the upper stems, and slender and pinnately lobed on the lower stems.^[2] The hairs conserve water by reflecting heat and reducing air movement across the leaf's surface.^[2][3]

The flowers are yellow and composite, looking much like true sunflowers, and sometimes grow to about 5 cm (2 in) wide.^[3] Both the (8–12) ray and disk flowers are yellow,^[3] with one flower head on each flowering stalk.^[2][6] The flower heads have 6–14 rays, which are darker towards the base, and several disk flowers.^[7] They bloom from May to August.^[4][5] The seeds have scales at the tip.^[3]

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.^[8]

The common name "woolly sunflower" is often used to describe any member of the genus Eriophyllum.

Varieties

Varieties include:^[2][4][6]

• Eriophyllum lanatum var. achillioides (DC.) Jeps. — California, Nevada, Oregon.^[9]
• 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.^[10]
• Eriophyllum lanatum var. croceum (Greene) Jeps. — Sierra woolly sunflower; endemic to the Sierra Nevada in California.^[11]
• Eriophyllum lanatum var. grandiflorum (A.Gray) Jeps. — Large flowered woolly sunflower; northern California, Oregon.^[12]
• 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.^[13]
• Eriophyllum lanatum var. integrifolium (Hook.) Smiley — Oregon sunshine; California, Idaho, Montana, Nevada, Oregon, Utah, Washington, Wyoming.^[14]
• 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.^[15]
• 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 the San Bernardino Mountains in California.^[16]

Distribution and habitat

Eriophyllum lanatum is native to western North America. It is most common across California,^[4] also growing north through Oregon into British Columbia and east through Idaho into Wyoming, and through Nevada into Utah.^[4][17] This species has only been collected from Mexico once, on Guadalupe Island, and it is most likely extirpated there.^[18]

It can be found (for instance in California) in chaparral, oak woodland, mixed evergreen forest, and yellow pine forest and other conifer forests, grassland, and sagebrush scrub habitats.^[4] It commonly grows in dry, open places^[3] below 3,000 meters (10,000 feet) in elevation. It prefers full sun and well-drained soil, but it also grows on rocky slopes and bluffs.^[7]

References