(Heller) Chuang & Heckard
Castilleja exserta (formerly Orthocarpus purpurascens) is a species of plant in the genus which includes the Indian paintbrushes. Its common names include purple owl's clover, escobita, and exserted Indian paintbrush.
Castilleja exserta is an annual herb about 100-450 millimetres (4-18 in) tall with a hairy stem covered in thready leaves. Like other related Castilleja plants, this is a hemiparasite which derives some of its nutrients directly from the roots of other plants by injecting them with haustoria. This is the reason for its small, reduced leaves.
Although this species is variable in appearance and easily hybridizes with other Castilleja species, it generally bears a brightly colored inflorescence of shaggy pink-purple or lavender flowers. The thin, erect bracts are usually tipped with the same color, giving the inflorescence the appearance of a paintbrush.