African arrowroot by its scientific name Canna Indica is a plant of the Cannaceae family native to the Caribbean and tropical America. It has since spread to all tropical regions of the globe. Archaeological traces have proven its presence in Peru 4,500 years ago. African arrowroot is also called Indian shot, edible canna, purple arrowroot, Sierra Leone arrowroot. “Conflore” in Reunion Island and you can also find it under the name of “Balisier rouge”.
It is a perennial plant producing tufts of stems 150-300 cm high with large leaves resembling banana leaves that can reach 50 cm long and 25 cm wide. The stems come from a large, thick, tuberous rhizome.
The flowers, red, pink, yellow or orange in color, are hermaphroditic and are visible all year round in tropical regions.
The fruits are globular and warty capsules, 1.5 to 3 cm long, brown in color when ripe, which contain about fifteen seeds.
The seeds the size of a pea are shaped like shiny black beads and very dense and very leathery.
Canna is widely cultivated throughout the tropics and subtropics as an ornamental plant, being particularly valued for its attractive flowers and leaves.
The root of the plant provides food, medicine and cosmetics. The medicinal virtues are numerous.
In Martinique, the starch from the rhizomes was used in the diet of infants and the elderly. This has become rarer today. It is obtained by grating the root into a pulp, then washing it to filter it and eliminate the fibers after the drying stage comes. The roots can be peeled, dried and then ground into flour. It is from this flour that what is called toloman is prepared.
Flour is made up of over 90% starch and around 10% sugar (glucose and sucrose). The starch produced is a shiny yellowish powder with very large grains of irregular shape. It is very soluble and easily digestible. After cooking, the starch is shiny and transparent.
In Peru, very young tubers are cooked for up to 12 hours, after which they become a white, translucent, fibrous and somewhat mucilaginous mass with a sweet taste.
The plant is used for the treatment of gynecological pain in women.
The root is diaphoretic (promotes sweating) and diuretic. Toloman is also used in the treatment of fever. The root is sometimes eaten raw but more often it is cooked in different ways to be eaten.
A root decoction, combined with fermented rice, is used in the treatment of gonorrhea and amenorrhea.
The rhizome infusion is said to be febrifuge and stimulating, while the decoction is said to be diaphoretic and diuretic.
The rhizome is also transformed into an emollient poultice. It is considered mature when the triangular slit in the rhizome's outer scale leaf has turned purple.
It is highly likely that the above reports for rhizome and root uses actually refer to the same part of the plant, although it is also possible that the rhizome refers to the swollen tuberous root, while the root refers to the thinner roots.
The leaves are diuretic and emollient. The powdered leaves and seeds are mixed and used to treat skin diseases.
The young shoots are cooked and eaten as a green vegetable while the immature seeds are cooked in tortillas.
The seeds are softening. They are mixed with water in a poultice which is placed on the forehead to remedy headaches. They can also be ground into powder and used as an anti-infective agent or as a treatment for itching, persistent wounds.
How to grow it
Toloman is a plant of the humid tropics where it can be found up to altitudes of up to 2,000 meters. It can also be grown in subtropical and warm temperate areas. It grows best in areas where annual daytime temperatures are between 12 and 32°C. The top growth can be killed even by light frosts, but the rootstock can survive several degrees of frost.
It prefers an average annual rainfall of between 1,000 and 4,500 mm, but tolerates between 500 and 5,000 mm.
Toloman requires deep, well-drained soil in a sunny position.
The plant has large leaves and does not like windy conditions as this can tear the leaves to shreds.
The plant is widely cultivated as an ornamental and selected forms are cultivated for their edible roots.
Plants grow quickly and can produce a flowering shoot in their first year of growth from seed.
Rhizome cuttings turn into harvestable plants 6-8 months after planting. To make them germinate, it is also necessary to let them soak in water for 2 to 3 days.
Plants grown from the rhizome tips can be harvested 4 months after planting, but harvesting after 8 months gives higher yields as the rhizomes have swelled to their maximum. The rhizomes should not age much more than 10 months as they become leathery and less suitable for consumption or starch production.