Mabberley, D. J. 2008: Mabberley's plant book, a portable dictionary of plants, their classification and uses. 3rd ed. Cambridge University Press. 1021 p.
The Global Biodiversity Information Facility:
GBIF Backbone Taxonomy, 2013-07-01.
Accessed via http://www.gbif.org/species/640 on 2015-02-01
This backbone name usage exists because it was found in another checklist at the time the backbone was built. The primary source name usage has since been removed from the portal.