purple owl's-clover

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 species is a hemiparasite, deriving some of its nutrients directly from the roots of other plants by infiltrating them with haustoria. As a result, its own leaves are small and reduced. 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.

Varieties. Varieties include:

Castilleja exserta var. exserta — pale purple owlclover. Castilleja exserta var. latifolia — wideleaf Indian paintbrush; endemic to coastal California. Castilleja exserta var. venusta — endemic to California: Mojave Desert, southern San Joaquin Valley.