Peganum L. is a genus under the recently separated family Nitrariaceae. Formerly it used to be included in the family Zygophyllaceae.
Phylogeny and Species The genus has around five species, occurring in warm temperate to subtropical regions across the world: Peganum harmala L. (Harmal or Syrian rue) — Mediterranean region east to China Peganum mexicanum Gray — Mexico Peganum multisectum (Maxim.) Bobrov — China, Mongolia Peganum nigellastrum Bunge — China Peganum texanum M.E.Jones — southern North America
Phylogenetic data suggests the following relationships:
References