A genus of 3 species, herbs parasitic on Quercus section Lobatae (red oaks) of e. North America and sw. North America south to Central America. Rodrigues, Colwell, & Stefanović (2011) and Rodrigues et al. (2013) determined that a division of the genus into 3 species best reflects genetic differentiation, the other 2 being C. alpina Liebmann, ranging from AZ, NM, and TX south to s. Mexico, and C. panamensis Woodson of Costa Rica and Panama.
Ref: Collins, Colwell, & Yatskievych (2019a) In Flora of North America Editorial Committee (2019); Haynes (1971); Rodrigues et al. (2013); Rodrigues, Colwell, and Stefanović (2011); Thieret (1971). Show full citations.