Common Name: Indian Shot

General Information

Canna indica is a perennial plant producing clumps of stems 150 - 300cm tall, with large leaves up to 50cm long and 25cm wide. The stems arise from a large, thick and tuber-like rhizome[]. With its large leaves sheathing a central stem, the plant has the appearance somewhat like a small banana plant.
The plant provides food (especially the root), medicines and a range of commodities. It is often cultivated on a home scale for these uses, especially in S. America and southeast Asia; whilst it is grown on a small scale in Australia as a commercial source of arrowroot. The plant is widely grown through the tropics, subtropics and warm temperate zone as an ornamental, being valued especially for its flowers and attractive leaves[].

Known Hazards

None known

Botanical References

, ,

Range

S. America - Argentina, Uruguay, Paraguay, northwards through C. America to Mexico and Texas; through the Caribbean to Florida, S. Carolina.

Habitat

Mostly in moist or wet thickets, or along streams, frequent in secondary growth, often invading cultivated ground, especially coffee plantations, at elevations from near sea level to 1,900 metres[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Perennial
Height	1.50 m
Pollinators	Hummingbirds
Cultivation Status	Cultivated, Ornamental, Wild

Cultivation Details

A plant of the moist tropics, where it can be found at elevations up to 2,000 metres. It can also be cultivated in the subtropical and warm temperate zones. It grows best in areas where annual daytime temperatures are within the range 12 - 32°c. Top growth can be killed by even light frosts, but the rootstock can survive several degrees of frost[]. It prefers a mean annual rainfall in the range 1,000 - 4,500mm, but tolerates 500 - 5,000mm[].
Requires a deep rich well-drained soil in a sunny position[, ]. Prefers a pH in the range 5.5 - 7.5, tolerating 5 - 8[]. The plant has large leaves and dislikes windy conditions since this can tear the leaves to shreds[].
The plant is widely grown as an ornamental, and selected forms are cultivated for their edible roots.
Plants are fast-growing, and can produce a flowering shoot in their first year of growth from seed[].
Rhizome cuttings develop into harvestable plants in 6 - 8 months from planting[].
Plants grown from rhizome tips can be harvested 4 months after planting, but harvesting after 8 months gives higher yields, because then the rhizomes have swollen to their maximum. Rhizomes should not be allowed to become much older than 10 months as they become tough and less suitable for consumption or starch production[].
A rhizome is considered mature when the triangular slit in the outer scale leaf of the rhizome has turned purple[].
Rhizome yield ranges from 23 tonnes per hectare at 4 months; to 45 - 50 tonnes at 8 months; to 85 tonnes after a year. Reported starch yields are 4 - 10 tonnes, exceptionally 17.5 tonnes per hectare[]
This species is often grown as a summer bedding plant in the temperate zone, especially in sub-tropical bedding schemes.
This species is probably hardy in the mildest areas of the temperate zone but even then it should be given a good mulch if left in the ground overwinter[, ]. Plants have survived temperatures down to about -5°c overwinter in our Cornwall, England garden[]. In colder areas of the country the tubers can be harvested in late autumn after the top growth has been killed back by frost and stored over winter. They should be kept in a cool but frost-free place covered in moist soil or leaves[].
Slugs love the young growth in spring and can cause serious damage to plants[].

Edible Uses

Root - sometimes eaten raw, but usually consumed after being cooked in various ways. The very young tubers are eaten cooked, they are sweet but fibrous[, ]. In Peru they are baked for up to 12 hours, after which time they become a white, translucent, fibrous and somewhat mucilaginous mass with a sweetish taste[]. Roots contain about 25% starch[].
The roots are the source of 'canna starch', which is used as an arrowroot[, ]. It is obtained by rasping the root to a pulp, washing and straining to get rid of the fibres and then drying[]. Alternatively, the roots can be peeled, dried and then ground into a flour[]. The flour consists of more than 90% starch and about 10% sugar (glucose and sucrose). The starch produced is a shiny yellowish powder with very large (125 - 145 µm 60 µm) irregularly shaped grains. It is highly soluble and easily digestible. After cooking, the starch is glossy and transparent[].

Young shoots are cooked and eaten as a green vegetable[].
The leaves are used for wrapping other foods[].

There is one report that this plant has an edible fruit[] but this is somewhat dubious, the fruit is a dry capsule containing the very hard seeds[]. The immature seeds are cooked in tortillas[].

Medicinal

The plant is used in the treatment of women's complaints[].

The root is diaphoretic and diuretic[, , ]. It is used in the treatment of fevers[]. A decoction of the root, combined with fermented rice, is used in the treatment of gonorrhoea and amenorrhoea[].
An infusion of the rhizome is said to be febrifuge and stimulant , whilst a decoction is said to be diaphoretic and diuretic[]. The rhizome is also made into an emollient cataplasm[].
It is quite probable that the reports above for the uses of the rhizome and the roots actually refer to the same part of the plant, though it is also possible that the rhizome refers to the swollen tuberous root, whilst root refers to the thinner roots[].

The leaves are diuretic and emollient[, ].

The leaves and the powdered seeds are mixed and used to treat dermatoses[].

The seeds are demulcent. They are mixed with water in a poultice which is placed on the forehead to remedy headaches[]. They are ground into a powder and used as an anti-infective agent or as a treatment for itches, persistent sores and 'bush yaws'[].

Other Uses

The plant yields a fibre - from the stem? - it is a jute substitute[]. A fibre obtained from the leaves is used for making paper[]. The leaves are harvested in late summer after the plant has flowered, they are scraped to remove the outer skin and are then soaked in water for 2 hours prior to cooking. The fibres are cooked for 24 hours with lye and then beaten in a blender. They make a light tan brown paper[].

The large leaves are sometimes used as plates[].

A purple dye is obtained from the seed[]. It is not very permanent[].

Smoke from the burning leaves is said to be insecticidal[].

The hard seeds are used as the 'rattle' in rattles[]. They are also used as beads to make rosaries and necklaces[, ].

Propagation

Seed - the different species in this genus often hybridize and so seed cannot be relied upon to breed true. If growing from seed, pre-soak for 24 hours in warm water and sow in the seeds in late winter/early spring, 2 - 5cm deep in individual pots in light shade in a greenhouse at 20°c[, ]. Scarifying the seed by carefully removing a small part of the outer shell (being careful not to harm the seed itself), to enable it to imbibe water can speed germination, especially if the seed has not swollen after being soaked[, ]. The seed usually germinates in 3 - 9 weeks[]. Grow the plants on in a greenhouse for at least their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts.
Division of the root clump as the plant comes into growth in the spring. Each portion must have at least one growing point. Pot up the divisions and grow them on in the greenhouse until they are well established and then plant them out in the summer.
Root cuttings.