Castilleja thompsonii

Common Names

Thompson's Indian Paintbrush, Thompson's Paintbrush, Thompson's Owl Clover

Summary

Thompson's paintbrush is a native perennial hemiparasitic herb of the Pacific Northwest, with erect to ascending stems 10–40 cm tall and hirsute maroon-tinged foliage. Lower leaves are linear, upper leaves 3–5 linear lobes, and inflorescence bracts are yellowish-tinged surrounding a maroon calyx 12–25 mm long that largely encloses a greenish corolla; flowers bloom May–September in seasonally dry sagebrush shrublands and open rocky ridges at elevations of 200–2100 m, often in association with Artemisia (sagebrush).

In cultivation, the hemiparasitic habit requires a compatible host for water and minerals, with Artemisia spp. often serving as hosts, reflecting the plant's native affinity for sagebrush habitats and thin, well-drained soils at 200–2100 m elevation.

Lifecycle

Perennial

Height

4-16 inches

Sunlight Requirements

Ideally full sun.

Soil Type

Thin, rocky, well-drained soils (scabland lithosols), often sandy or gravelly with low organic matter.

Soil Drainage

Well-drained soils

Soil pH

Alkaline (calcareous) soils

Bloom Color

Yellow to greenish yellow blooms, with maroonish to reddish bases and cream to pale yellow-green upper parts

Bloom Time

Spring through Fall

Foliage Color

Greenish yellow

Fall Foliage Color

Green to purple or reddish brown, yellowish, yellowish-tinged

Growth Rate

Growth rate not specified.

Seasons of Interest

Spring and Summer

Propagation Methods

Seeds (wind or gravity dispersal)

Attracts Wildlife

Attracts bees, hummingbirds, and birds