Orthocarpus

Orthocarpus, or owl's-clover,^[1] is a genus of flowering plants in the family Orobanchaceae (broomrapes). They are native to North America. A number of species formerly included in Orthocarpus have been transferred to the genus Castilleja, which includes the plants commonly known as Indian paintbrush. Plants of the genus are generally less than 30 centimetres (1 ft) in height.^[2]

Orthocarpus
Orthocarpus tenuifolius
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Asterids
Order:	Lamiales
Family:	Orobanchaceae
Genus:	Orthocarpus Nutt.
Species
See text.

Like their close relatives in genus Castilleja, Orthocarpus are root hemiparasites, capable of photosynthesis but extracting water and mineral nutrients through attachment to the roots of host plants.

Some animal species such as the Edith's checkerspot butterfly use these plants as hosts during ovipositing.^[3]

Species

As of March 2022^[update], Plants of the World Online accepted the following species:^[4]

• Orthocarpus barbatus J.S.Cotton
• Orthocarpus bracteosus Benth.
• Orthocarpus cuspidatus Greene
• Orthocarpus holmgreniorum (T.I. Chuang & Heckard) L. M. Shultz & F. J. Smith
• Orthocarpus imbricatus Torr. ex S.Watson
• Orthocarpus luteus Nutt.
• Orthocarpus pachystachyus A.Gray
• Orthocarpus purpureoalbus A.Gray ex S.Watson
• Orthocarpus tenuifolius (Pursh) Benth.
• Orthocarpus tolmiei Hook. & Arn.