If you have the fortune to be botanizing in southwest Washington, you might have the chance to encounter one of Washington’s rare paintbrush species. At first glance you might think this is the common, harsh paintbrush (Castilleja hispida) since both species have the same vibrant, orange-colored bracts and both are found at low to mid elevations. But it is in fact Chamber’s paintbrush (Castilleja chambersii), and when you look more closely at the leaves, you will see what is so unusual about this species. The leaves are alternate, sparsely hairy or glabrous, and deeply lobed, with the 3-7 (or more) lobes erect to ascending, linear to lance-shaped, and pointed at the tip.

This species is locally endemic of the Pacific Coast Range in northwestern Oregon and southwestern Washington in Pacific County on both sides of the Columbia River. Chamber’s paintbrush is found at elevations from 630-950 meters in the coastal mountains. In both Washington and Oregon, Chamber’s paintbrush is ranked as S1, or Critically Imperiled, and globally it is ranked as G1- Critically Imperiled. There are only five known populations across its entire range.

In Washington State we only know of one population, located on private land. The species is named for Oregon State University botanist Kenton Chambers who collected specimens of this special paintbrush in Clatsop County, Oregon in 1973 and 1974. It wasn’t until 1999 that the species was officially described by E. Mark Egger. The Washington population was not discovered until a specimen was collected in 2015 by Weyerhaeuser Company forester Kristi Tausch. This voucher extended the known range of Chamber’s paintbrush 70 kilometers north.

The population is made up of six sub-populations all within 1 kilometer of each other. It grows in wet crevices and ledges on basaltic cliffs within a matrix of managed Douglas-fir (Pseudotsuga menziesii) and western hemlock (Tsuga heterophylla) forest. Staff from the Washington Natural Heritage Program, DNR Natural Areas Program and Rare Care met recently with a plant ecologist and forester from Weyerhaeuser to visit the population and provide input on their conservation efforts. Rare Care also collected seeds for the Miller Seed Vault.

Suitable habitat for Chamber’s paintbrush appears to be relatively extensive in this part of Pacific County, and further fieldwork on seeping, rocky slopes in the correct elevation range may well uncover more populations. Additional searching would augment our understanding of the vulnerability of this special species.