What is "pholisma"

The genus Pholisma (Nutt. ex Hook.) consists of three to five species of desert-dwelling, primarily subterranean plants.

Most notable of the genus is Pholisma sonorae, native to the Southwestern United States and Mexico. The species is without chlorophyll and lives as a parasite on the roots of a number of desert species. Pholisma belongs to the family Boraginaceae. Other species include Pholisma arenarium, the "desert Christmas tree".