T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network


Canna indica (Indian shot)

Kingdom: Plantae
(unranked): Angiosperms
(unranked): Monocots
(unranked): Commelinids
Order: Zingiberales
Family: Cannaceae
Genus: Canna
Species: C. indica
Binomial name: Canna indica
Common names: Canna lily, Indian shot.

Canna indica is a native of the south eastern United States, Mexico, Central America, West Indies and much of South America. It is now naturalised in many parts of the world including New Zealand. In New Zealand it is an environmental weed of waterways, lakes, ponds, swamps and other wetland habitats. Sometimes also found growing in old gardens, disturbed sites and waste areas. It forms large long-lived dense clumps, particularly along waterways and along the margins of water bodies where it replaces native aquatic and wetland species.
Canna indica is an erect unbranched perennial growing up to 1-2m tall. It spreads laterally by means of fleshy underground rhizomes and by seeds.

The stems (1-2 m tall) are upright sturdy, glabrous and green in colour. The green leaves are alternatively arranged and consist of a stem-clasping sheath at the base and a very large, spreading, leaf blade (20-60 cm long and 10-30 cm wide).

Flowering occurs mainly during spring and summer. The flowers can be either red, yellow or occasionally red and yellow (i.e. yellow with red spots or vice versa). They are hermaphrodite and have five false 'petals' (i.e. four petaloid staminodes and a petaloid filament) that are relatively narrow (less than 15 mm wide). The actual petals are fused together at the base.

The fruit are initially green and are covered with small projections (verrucose). They turn brown as they mature and split open to release very hard, numerous, smooth, black, rounded seeds (4-7 mm wide). Fruiting occurs mainly during summer and early autumn. In many hybrid cannas in cultivation, the seeds are more oblong-shaped.

The canna indica species have been used for the treatment of industrial waste waters through constructed wetlands due to its effective removal of high chlorinated organic compounds from paper mill waste water.

It is interesting that its common name 'Indian shot” is because in the 18th century the BB-like seeds of Canna indica were used in flintlocks when lead pellets were scarce or unavailable.



Photo showing flower,  green imature seed capsules and a mature brown capsule split open with the hard brown round seeds visable.