Visiting Canna discolor var. discolor (Lindl.) Nb.Tanaka

A tall species; green and purple variegated foliage, oval shaped, maroon margin, spreading habit; spikes of flowers are erect, self-coloured crimson, staminodes are long and narrow, edges regular, fully self-cleaning, average bloomer; seed is sterile, pollen is sterile; rhizomes are thick, up to 7 cm in diameter, coloured white and pink; tillering is prolific.

More than other Canna species, C. discolor is used extensively in agriculture in Asia. It grows high yields of very large rhizomes, sometimes the size of a man's arm, exceedingly rich in starch. Still planted in Indian villages as a minor crop.


Discolor means 'two-coloured-leaved', and introduced to England from Trinidad, 1827 (Johnson's Dictionary 1856). Found by the coast of South America, the West Indies and in temperate valleys of the Andes. Usually found at the edges of moist thickets or in ditches.

Dr. Maas considers Canna discolor to be a synonym of C. indica L., however, Dr Tanaka's studies have revealed that C. indica can be clearly distinguished from other taxa. It is a triploid, and is sterile both ways.

Synonyms: C. 'Achira Dark', C. 'Brick', C. 'Brick canna', C. discolor

Introducing Canna 'Tama-Tulipa'

A medium sized Foliage Group cultivar; glaucous green foliage, lanceolate shaped, upright habit; clusters of flowers are upright, yellow rayed with cardinal-red, staminodes are long and narrow, edges regular, fully self-cleaning; fertile both ways, not true to type, self-pollinating, capsules globose; rhizomes are long and thin, coloured white and pink; tillering is slow.

Introduced by Carl Schoenfeld of Yucca-Do Nursery. Dr. Tanaka commented that this is most likely a naturally occurring hybrid between Canna glauca and Canna indica. This makes sense because it was discovered geographically centred between the ranges of the two species.

Describe Cannas: Rhizomes

It was Dr Nobuyuki Tanaka, the Japanese taxonomist, who created a set of working measurements for Canna rhizomes, and he used them to help him categorize the wild species, resulting in his Taxonomic revision of the family Cannaceae in the New World and Asia in 2001. This revision was the start of bringing order to the chaos we had previously experienced in naming of our Canna species. The categories defined by Tanaka are:

1. thick, up to 3 cm in diameter
2. thick, up to 7 cm in diameter
3. long and thin
4. tuber-like groups
5. no rhizomes
   

To the first four specified by Tanaka, we have added the fifth category. At Claines Canna we have grown C. paniculata that did not have any rhizomatic growth, and Dale McDonnell, in Australia, has had this same experience, having inherited an old Foliage Group specimen that displays the same characteristic.

We have used this classification for some years now, and we cannot find any fault with it.

Wild species tamed

It has long been the practice when writing about Cannas to assert that the species are in total disarray, nobody knows how many there are or what the hundreds of published names are synonyms of. That is no longer the case.

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.

References:

• 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.