canna, (genus Canna), genus of about 10 species of flowering plants, the only genus of the family Cannaceae (order Zingiberales). The plants are distributed from southeastern North America through South America. Many are cultivated as ornamentals for their showy flowers and attractive foliage, and a number of cultivars have been developed. Edible canna, or Indian shot (Canna indica), and achira (C. discolor) have edible starchy rhizomes and are grown agriculturally in some places; the latter is sometimes listed as a synonym of C. indica.

Canna are tropical herbs and possess rhizomes (underground stems) with erect stems growing to 3 metres (10 feet) high. The tall or dwarf foliage displays spirally arranged leaves that may be green or bronze. The flowers are asymmetrical, with one half-functional stamen and a labellum, a petal-like structure rolled outward. The two to three “petals” are actually sterile stamens (staminodes); there are also three regular petals. Sometimes spotted variations of the scarlet, red-orange, or yellow flowers occur.