Dr Nobuyuki Tanaka is a botanist at the Tokyo Metropolitan University and at the Makino Botanical Garden in Kochi prefecture, Japan. He has published a full taxonic revision of the Canna species and he has identified 19 species as being distinct and separate.
In addition, the botanists at Kew Gardens have assigned all of the published species names to one of the 19 accepted species, i.e. sorted the synonyms.
The original Canna checklist at Kew Gardens can be located at: http://www.kew.org/wcsp/.
The Wikipedia has a separate article for Canna species, containg both the accepted species, plus all of the synonym names linked to the species. That article can be found at: http://en.wikipedia.org/wiki/List_of_Canna_species and reflects both the taxonic revision and the Kew checklist.
- Tanaka, N. 2001. Taxonomic revision of the family Cannaceae in the New World and Asia. Makinoa ser. 2, 1:34–43.
Well done to everyone concerned... now if we can find a source of Canna liliiflora seed, then I'd be totally happy.