About 4, see text Parentucellia is a small genus of flowering plants in the family Orobanchaceae containing about four species.

The genus was named for Pope Nicholas V, whose surname was Parentucelli.

[3] The phylogeny of the genera of Rhinantheae has been explored using molecular characters.

It is closely related to the genus Bellardia, and then to Odontites, Tozzia and Hedbergia.

In turn, these genera share phylogenetic affinities with Euphrasia and Bartsia.