George Engelmann: Synopsis of the Cactaceae of the Territory of the United States and Adjacent Regions. In: Proceedings of the American Academy of Arts and Sciences. Band 3, 1856, S. 280–281 (online).
doi.org
Nadja Korotkova, David Aquino, Salvador Arias, Urs Eggli, Alan Franck, Carlos Gómez-Hinostrosa, Pablo C. Guerrero, Héctor M. Hernández, Andreas Kohlbecker, Matias Köhler, Katja Luther, Lucas C. Majure, Andreas Müller, Detlev Metzing, Reto Nyffeler, Daniel Sánchez, Boris Schlumpberger, Walter G. Berendsohn: Cactaceae at Caryophyllales.org – a dynamic online species-level taxonomic backbone for the family – Electronic supplement. In: Willdenowia. Band 51, Nr. 2, 2021, S. 94–95 (doi:10.3372/wi.51.51208).
google.de
books.google.de
Charles Lemaire: Les Cactées. Histoire, Patrie Organes de Vegetation, Inflorescence Culture etc. Paris 1868, S. 57 (online).