Castilleja exserta Purple owl's clover is an erect annual. It grows a foot or more tall and has branching stems with alternate leaves deeply and pinnately cleft into narrow filiform divisions. The flowers are in dense terminal spikes subtended by bracts which are 5-7 palmately lobed, greenish and hairy at the base, greenish-purple in the middle, and velvety rose-purple at the tips. The calyx is divided 1/2 in front, 1/3 on the sides, and 2/3 in the back and is the color of the bracts. The corolla is shaggy-hairy, two-lipped, and barely exserted, the galea or upper lip reddish and somewhat hooked at the tip, the lower lip mostly lavender with yellow and/or white markings and purple dots. There are four stamens with puberulent filaments and a stigma which is more or less included. Owl's clover is partially parasitic and blooms from March to May on grassy slopes and openings in chaparral and coastal sage scrub below 3000'. It is highly variable and hybridizes with several other Castilleja species