Sulphur Indian Paintbrush
Castilleja septentrionalis
Broomrape/Paintbrush family (Orobanchaceae)
This delicately colored paintbrush ranges from a light yellow to yellow/white. Sulphur Paintbrush is taller (growing to 15 inches) than its cousin Western Paintbrush (Castilleja occidentalis) (growing to 8 inches). The range of the two also helps identify the two: Western Paintbrush grows above timberline and Northern Paintbrush grows below. C. septentrionalis hybridizes with the gorgeous iridescent Rose Paintbrush, C. rhexifolia, producing exotic variants of rose-pink/lavender/yellow paintbrush.
Per Axel Rydberg named this species in 1900 from a specimen collected by Rydberg and Bessey in Yellowstone National Park in 1897.

© Mary Ellen (Mel) Harte, Bugwood.org