Golden paintbrush was listed as threatened, without critical habitat, on June 11, 1997

Description and Life History

Golden paintbrush is a perennial herb in the figwort or snapdragon family (Scrophulariaceae).  It often has from 5-to-15 unbranched stems. The stems may be erect or spreading, in the latter case giving the appearance of being several plants, especially when in tall grass.  Plants are up to 30 cm (12 inches) tall and are covered with soft, somewhat sticky hairs.  The lower leaves are broader, with 1-to-3 pairs of short lateral lobes near the terminal third.  The showy bracts are about the same width as the upper leaves, softly hairy and sticky, and are golden yellow.  The bracts effectively hide the flowers.

Golden paintbrush is short-lived and individual plants generally do not survive longer than 5-to-6 years.  This species apparently reproduces exclusively by seed; vegetative spread has never been observed or reported.  Plants may flower as early as February, and flowers are observed into summer.  The fruit is a capsule, which matures in August;  by mid-summer, the plants senesce, although some plants produce shoots in the fall that overwinter.  Capsules persist on the plants well into winter.  Although seed dispersal has not been directly observed, the seeds are probably shaken from the seed capsules and fall a short distance from the parent plant.  The seeds are light and could possibly be dispersed short distances by the wind.

Habitat

Habitat descriptions for golden paintbrush are based on those extant populations in Washington and British Columbia; absent comparable habitat information for Oregon, we assume that the habitat of the extirpated populations in the Willamette Valley was similar. Golden paintbrush occurs in upland prairies, on generally flat grasslands, including some that are characterized by mounded topography. Low deciduous shrubs are commonly present as small to large thickets. In the absence of fire, some of the sites have been colonized by trees, primarily Douglas-fir, and shrubs, including wild rose and Scotch broom, an aggressive non-native shrub.

The mainland population in Washington occurs in a gravelly, glacial outwash prairie. Other populations occur on clayey soils derived from either glacial drift or glacio-lacustrine sediments (in the northern end of the species’ historic range).  All of the extant populations are on soils derived from glacial origins. At the southern end of its historic range, populations occurred on clayey alluvial soils, in association with Oregon white oak woodlands.  Recent analyses of likely sites for reintroduction of golden paintbrush found that habitats are dominated by non-native annuals, and will require management before successful reintroductions can be expected

Reasons for Decline

Threats to golden paintbrush include habitat modification as succession causes prairies and grasslands to become shrub and forest lands; development for commercial, residential, and agricultural use; low potential for expansion of golden paintbrush populations and their refugia because existing habitat is constricted; and recreational picking and herbivory.

Range

Historically, golden paintbrush has been reported from more than 30 sites in the Puget Trough of Washington and British Columbia, and as far south as the Willamette Valley of Oregon.  Many populations have been extirpated due to agricultural, residential, and commercial development.  Eleven populations are currently known to exist in Washington and British Columbia; more than half of these populations occur on Whidbey, San Juan and Lopez islands off the north coast of the Washington mainland.  In Oregon,golden paintbrush historically occurred in the grasslands and prairies of the Willamette Valley in Linn, Marion and Multnomah Counties; the species has been extirpated from all of these sites as the habitat has been changed or modified by urbanization or agriculture.  The last sighting of golden paintbrush in Oregon was in 1938 in Linn County.

Conservation

Some research has been conducted on the population biology, fire ecology, propagation and restoration of golden paintbrush. The results of these studies have been used to direct the management of the species at sites managed for upland prairies, and are critical to the future reintroduction and recovery of the species.  A reintroduction plan has been prepared as directed by the golden Paintbrush Recovery Plan; reintroduction into likely historical habitat is the best hope for the species to recover in the prairies of Oregon and southwestern Washington. Greenhouse trials and surveys of potential reintroduction sites in the Willamette Valley have recently been completed.  Seeds of this species have been banked at the Berry Botanic Garden in Portland, Oregon and the University of Washington Botanic Garden.

References and Links

Caplow, F. 2004. Reintroduction Plan for Golden Paintbrush (Castilleja levisecta). Washington Natural Heritage Program, Washington Department of Natural Resources. Prepared for U.S. Fish and Wildlife Service, Western WA Fish and Wildlife Office. 44 pp. + appendices.

U.S. Fish and Wildlife Service. 2000. Recovery Plan for the Golden Paintbrush (Castilleja levisecta) U.S. Fish and Wildlife Service, Portland, Oregon. 51 pp.