The Canna Lily cultivars used for food come primarily from selections of Cannaindica (Tanaka's - Canna discolor).
Today food varieties are commonly designated Canna 'Achira'.
Garden Cannas have complex genetic input from Cannaindica, Cannaglauca, Cannaflaccida, Cannairidiflora, and Cannaliliiflora.
Of these, Cannaindica was the species originally brought into European gardens by Charles de l'Ecluse in 1576.
Normally the specific epithet 'indica' means 'from India' but in this case de l'Ecluse was referring to the West Indies (The Caribbean Islands).
Canna hybridization has crossed many of the wild species in a very complex manner.
Many epithets have been used in Canna breeding programs leading to names such as Cannahortensis, Cannahybrida, and Cannaorchiodes.
These have all been abandoned and for the sake of simplicity, all ornamental hybrids of Canna are now properly called Cannageneralis.
Usually, breeders do not mention the epithet 'generalis' when they write the name.
Modern Canna breeders have created 'cultivar groups' of C.
generalis in order to classify all modern hybrids by their most prominent phenotypic traits or historical sources.
The creation of cultivar groups is not uncommon in ornamental horticulture and is used for azaleas, camellias,daffodils andtulips too.
Currently, there are 10 cultivar groups of Cannas.
An individual cultivar may be assigned to more than one cultivar group if it has traits that fit into more than one.
1.
Foliage Group - The foliage group of Cannas have been bred primarily for their foliage.
These may also be known as Anne Cannas, Ehemann Cannas, Canna 'Ehemannii' or the invalid name C.
nepalensis.
2.
Crozy Group - Named after the prominent French Canna breeder of the late 1800's.
This group is characterized by closely grouped flowers, narrow staminodes with space in-between them, and a labellum that is small and often curled.
This group may also be known by the obsolete terms French Cannas or 'Gladiolus flowering Cannas'.
3.
Italian Group - This group has large fragile staminodes that are wide enough that there is no space between them.
They were initially created by crossing Crozy Group Cannas with C.
flaccida.
The flowers are loosely arranged.
The labellum is large, wide, and usually not curled.
This group may also be known by the obsolete terms 'orchid flowering group', or C.
orchiodes.
4.
Australian Group - This group was created by crossing Foliage Group plants with Italian Group plants to create individuals with large leaves and large flowers.
5.
Premier Group - Derived from the Italian group and from triploids, this group is characterized by large round florets without gaps between the staminodes.
6.
Variegated Group - Covers all variegated Cannas regardless of the type or cause.
7.
Conservatory Group - This group of Cannas has been selected because they thrive in greenhouse conditions.
Members of this group grow continuously all year long, are vigorous, early flowering, self-cleaning, and are generally easily propagated.
This group originated from a breeding program at Longwood Gardens by Dr.
Robert Armstrong.
8.
Aquatic Group - Cultivars that thrive as marginal water plants.
Many of these cultivars have lance-shaped foliage and long, thin rhizomes.
Parent species are often C.
glauca and C.
flaccida.
9.
Miniature Group - This group consists of cultivars under 20" (0.
5m) in height.
10.
Agricultural Group - All Cannas used in agriculture.
These tend to be sterile triploids selected for high starch production.
They may also be known as C.
'Achira' or the invalid Canna Lily species name C.
edulis.