They are registered with an International Cultivar Registration Authority (ICRA), which for the genus Canna is the Royal General Bulbgrowers' Association of the Netherlands (KAVB).
[2][3][4][5] The pioneer of this group was Monsieur Crozy of Lyons, France, who started breeding cannas as early as 1862, from stock originally developed by Théodore Année.
[7] Most of this group obtained its larger sized flowers from the introduction of Canna flaccida in the early 1890s by Dr Sprenger in Naples, Italy followed shortly afterwards by Luther Burbank in California, United States, with the same cross.
[2][3][4][7] The growing conditions in a conservatory are quite specialised and do not suit many cultivars, this group have been selected for thriving in this environment, required features being plant vigor, early flowering, foliar appearance, self-cleaning ability and good propagation qualities.
[2][3][4][7][10][full citation needed] Cultivars growing under 0.5m (19") high, the flowers should be in scale to the rest of the plant.
[2][4] Cultivars grown selectively for agricultural usage, normally for their very large rhizomes and a high starch yield.