[Groundsels and Butterweeds: The Genera Packera and Senecio in the Columbia River Gorge of Oregon and Washington]

Paleyellow Ragwort, Western Groundsel, White Western Groundsel

Senecio integerrimus var. ochroleucus

Synonyms: Senecio integerrimus ssp. ochroleucus, Senecio lugens var. ochroleuchus

Paleyellow Ragwort, Western Groundsel, White Western Groundsel: Senecio integerrimus var. ochroleucus (Synonyms: Senecio integerrimus ssp. ochroleucus, Senecio lugens var. ochroleuchus)

White western groundsel as seen atop Grassy Knoll, Gifford Pinchot National Forest..........May 15, 2015.

Characteristics:

Western groundsel is a stout, solitary stemmed perennial from a fibrous-rooted crown which grows from 20-70 cm tall. The stems may be branched slightly. The herbage is cobwebby-hairy when young, and tends to become smooth or glabrous with age. The basal leaves are petiolate with entire to irregularly toothed leaf margins. The basal leaves are commonly from 6-25 cm long and 1-6 cm wide. The stem leaves become reduced upwards, and become sessile.

The several to numerous flower heads often form a congested inflorescence. The involucre is usually 5-10 mm tall with the bracts in one row, each having a pointed, black tip (see upper photo). The flower heads usually have both disk and ray flowers. The rays are usually 6-15 mm long.


Varieties:

Senecio integerrimus var. vaseyi: Flower heads discoid. It may be found from the Cascade and Wenatchee Mts. of central Washington and possibly south through the Cascades to California.

Senecio integerrimus var. exaltatus: Flower heads yellow with both disk and ray flowers. The basal leaves tend to oblanceolate or elliptic in shape. It may be found east of the Cascade crest in dry woodlands and prairies from northern Washington south to the Columbia River gorge and possibly south to California. It is found eastward through Washington and Oregon to northern Idaho and Montana.

Senecio integerrimus var. ochroleucus: Flower heads white or creamy colored. The basal leaves tend to be deltoid or subcordate. (See lower photo.) It may be found in open areas across the range of the species.


Habitat:

Western groundsel is found from the lowlands to well into the mountains on open ground or open woods which are moist in spring and dry during the summer.


Range:

Western groundsel is found from southern British Columbia south to California, and east to Saskatchewan and Minnesota.

In the Columbia River Gorge, variety exaltatus is found from 200'-4400' in elevation from between approximately Multnomah Falls and the Columbia Hills. Variety ochroleucus is found between 100'-4200' in elevation from approximately the Wind River to about the Major Creek Plateau.


Importance/ Uses:

Western groundsel concentrates alkaloids from the soil, and so is poisonous to livestock. Early in the season, this hasn't become a problem yet, so it might be grazed by sheep, elk, and cattle. It is an indicator of overgrazing on rangeland.


Inflorescence of Paleyellow Ragwort, Western Groundsel, White Western Groundsel: Senecio integerrimus var. ochroleucus (Synonyms: Senecio integerrimus ssp. ochroleucus, Senecio lugens var. ochroleuchus) - Inflorescence of Paleyellow Ragwort, Western Groundsel, White Western Groundsel: Senecio integerrimus var. ochroleucus (Synonyms: Senecio integerrimus ssp. ochroleucus, Senecio lugens var. ochroleuchus)

Paleyellow ragwort blooming along the Augsberger Trail within the mile above the Dog Mountain trailhead, Columbia River Gorge..........May 7, 2014.

Inflorescence of Paleyellow Ragwort, Western Groundsel, White Western Groundsel: Senecio integerrimus var. ochroleucus (Synonyms: Senecio integerrimus ssp. ochroleucus, Senecio lugens var. ochroleuchus) - Basal and lower stem leaves of Paleyellow Ragwort, Western Groundsel, White Western Groundsel: Senecio integerrimus var. ochroleucus (Synonyms: Senecio integerrimus ssp. ochroleucus, Senecio lugens var. ochroleuchus)

Close-ups of the inflorescence and basal and stem leaves of white western groundsel as seen from lower sections of the trails on Dog Mountain in the central Columbia River Gorge...........May 4, 2011.

Paleyellow Ragwort, Western Groundsel, White Western Groundsel: Senecio integerrimus var. ochroleucus (Synonyms: Senecio integerrimus ssp. ochroleucus, Senecio lugens var. ochroleuchus) - Paleyellow Ragwort, Western Groundsel, White Western Groundsel: Senecio integerrimus var. ochroleucus (Synonyms: Senecio integerrimus ssp. ochroleucus, Senecio lugens var. ochroleuchus)

White western groundsel in bud at left atop Grassy Knoll, Gifford Pinchot National Forest............June 3, 2014. The photo at right shows white western groundsel in bloom atop the Mill Creek Ridge Preserve, Columbia Land Trust lands southwest of The Dalles, OR......April 22, 2018.

Inflorescence of Paleyellow Ragwort, Western Groundsel, White Western Groundsel: Senecio integerrimus var. ochroleucus (Synonyms: Senecio integerrimus ssp. ochroleucus, Senecio lugens var. ochroleuchus) - Paleyellow Ragwort, Western Groundsel, White Western Groundsel: Senecio integerrimus var. ochroleucus (Synonyms: Senecio integerrimus ssp. ochroleucus, Senecio lugens var. ochroleuchus)

White western groundsel as seen at Catherine Creek.........April 13, 2016.

Inflorescence of Paleyellow Ragwort, Western Groundsel, White Western Groundsel: Senecio integerrimus var. ochroleucus (Synonyms: Senecio integerrimus ssp. ochroleucus, Senecio lugens var. ochroleuchus) - Inflorescence of Paleyellow Ragwort, Western Groundsel, White Western Groundsel: Senecio integerrimus var. ochroleucus (Synonyms: Senecio integerrimus ssp. ochroleucus, Senecio lugens var. ochroleuchus)

White western groundsel blooming in a forest opening under the powerlines above the Starvation Creek trailhead, Columbia River Gorge..........April 26, 2015.

Inflorescence of Paleyellow Ragwort, Western Groundsel, White Western Groundsel: Senecio integerrimus var. ochroleucus (Synonyms: Senecio integerrimus ssp. ochroleucus, Senecio lugens var. ochroleuchus) - Paleyellow Ragwort, Western Groundsel, White Western Groundsel: Senecio integerrimus var. ochroleucus (Synonyms: Senecio integerrimus ssp. ochroleucus, Senecio lugens var. ochroleuchus)

The photo at left shows the inflorescence of white western groundsel and its distinctive whitish ray flowers. Photographed along Forest Rd K3000 below Bird Creek Camp at approximately 2450' on the southeastern side of Mt. Adams..........May 7, 2005. The photo at right shows white western groundsel in bloom at Mill Creek Ridge Preserve, a Columbia Land Trust property outside The Dalles, OR......April 28, 2019.

Paul Slichter