Indian paintbrush has hairy, upright stems with flowers clustered at the top. The actual flowers are inconspicuous, tubular, greenish-yellow, and nestled in the axils of the brilliantly colored bracts, which can be red, orange, or yellow. Blooms April–July. Basal leaves formed during first year, short, oblong, with rounded ends. Stem leaves alternate, stalkless, narrow to linear to 3-lobed with the central lobe wider and longer than the other 2. Both leaf types are very hairy.
Similar species: There are two other species of Castilleja in Missouri, both Species of Conservation Concern. Downy painted cup (C. sessiliflora) lacks the "paint," with only green bracts surrounding the flowers; its flowers protrude noticeably beyond the bracts. It's found only in our far northwestern counties. Purple paintbrush (C. purpurea) has purple bracts instead of red and has clustered flowering stems. Rare and known only from a few locations in southwestern Missouri, it may not occur in our state anymore.