It is often forgotten that Cannaceae is a vegetable, that was turned into a garden cultivar by early horticulturists.
Although originating only in the tropical and semi-tropical Americas, the genus is now found all over the world. The early explorers did not take Cannas to Japan and China because of love for the foliage and flowers , but because it was a fast growing vegetable that filled their empty stomachs.
Fast food suggestions
Canna tubers can be used all year round, as a potato substitute. Peel the tubers and cut them into chips, then bake in the oven until golden brown, the flavour is improved by a sprinkle of garlic salt. Alternatively, cut into cubes when they can then be added to soups, or steamed like potatoes, until tender.
Young tubers have the best flavour, and the older ones are fibrous.
Arrowroot flour
To make arrowroot flour peel the tubers and cut into 2-4 cm cubes and blend with water to a pulp, or mince finely. Tip the pulp into a large bowl and add water. The flour will quickly settle to the bottom and the brown fibrous pulp can be drained off the top. Continue to rinse until the water runs clear. Drain off the water and pour the white flour into trays, 1-2 cm thick. Dry in the sun until soft and powdery.
The flour keeps well and can be used as a thickener. To thicken to a light syrup use 2 level teaspoons of arrowroot to each cup of water, heat, stirring until thick.
Connoisseurs tastes
It is asserted by some that all Canna rhizomes are eatable, but like all vegetables, different varieties will have different tastes and properties, and personally I would be reluctant to eat rhizomes from garden cultivars. Eating them would feel a bit like cannibalism to me, and remember, they have not been selected for taste, only their vegetative looks. In addition, we should recall that whilst the food industry has strict rules over what chemicals they can use, there are few of such rules governing the ornamental flower industry.
Agriculture Group
The species grown mainly in Asia for food is Canna discolor. This is an interesting species, as not only does it grow very large rhizomes, but it is also the only Canna wild species that is seed sterile, indicating that it is a triploid, as stated by the premier authority, Dr Khoshoo, and confirmed by Dr Tanaka in his revision of the Canna species.