Welcome to the Cannaceae scratchpad
The Cannaceae is a family of tropical plants including just one genus: Canna L. The family is originally Neotropical: species found in Africa and Asia are all considered to be of neotropical origin (Maas 2008). The genus comprises 10 species.
The large rhizomatous herbs have white, yellow, orange or red flowers in terminal inflorescences. The leaves are spirally arranged along the stem and have open leaf sheaths.The flowers are asymmetric, consisting of 3 greenish sepals, 3 variously coloured petals, several petal-like staminodes, and 1 petal-like fertile stamen. This stamen has only 1 theca. The style is also petal-like. All the petal-like flower parts are basally united into a floral tube on top of the inferior ovary. The fruit is a 3-locular capsule crowned by the persistent sepals; its wall is covered by soft green tubercules. The old fruit is brown and woody with woody tubercules. The seeds are black to dark brown, globose to ellipsoid and with a very hard seed coat. They open by an imbibition-lid only after having been exposed for 24 hours in a wet environment at 50 degrees Celsius (Graven et al. 1997). Therefore seeds can be viable after long periods. Canna-seeds found in an Argentinian tomb have been able to germinate after approximately 550 years (Sivori et al. 1968).
The flowers show secondary pollen presentation: in bud the pollen is already deposited on the petal-like style where it is easily accessible when the flower opens to possible pollinators (Yeo, 1993). Pollinators are largely unknown (bats, moths, and hummingbirds have been reported).
The seeds are dispersed by being strewn out of the capsule when moved by the wind or touched by passing animals (semachorous).
Canna’s have been, and still are, widely cultivated all over the Tropics and Subtropics, They have often escaped and are naturalized.
The have been cultivated for their rhizomes containing starch, and for their showy flowers (especially hybrids of natural species).
Paul Maas and Hiltje Maas-van de Kamer