American biogr. arch., 1986. Dizionario biografico universale / G. Garollo, 1907
BN Cat. gén.
Catalogue of North American genera of plants, arranged according to the orders of
Lindley's "Introduction to the natural system of botany", with the number of species
belonging to each genus as far as they are at present determined / by John Torrey,
1995 [document électronique : reprod. de l'éd. de 1831]