Canna glauca is a species of the Canna genus, a member of the family Cannaceae. It originates from the wetlands of tropical America and was introduced to England in 1730. The species is native to the southeastern and south-central United States (Texas, Florida, Louisiana and South Carolina) as well as Mexico, Central America, South America and the West Indies. It is also reportedly naturalized in Sri Lanka, Thailand, Vietnam, Java and the Philippines.
Canna glaucais a perennial growing to 1.5m. It is hardy to zone 10 and is frost tender. In the north latitudes it is in flower from August to October, and the seeds ripen in October. The flowers are hermaphroditic.
In the last three decades of the 20th century, Canna species have been categorised by two different taxonomists, Paulus Johannes Maria Maas from the Netherlands and Nobuyuki Tanaka from Japan. Inevitably, there are differences in their categorisations.
Both agree that C. glauca is a distinct species, but in addition, Tanaka also recognises two varieties:
- Canna glauca var. glauca
It is aquatic species, with narrow, blue-green (glaucous) leaves, atop of which sit its large, delicate, pale yellow flowers. It grows as a marginal plant in up to about 15 cm of still or slow-moving water.
- Canna glauca var. siamensis (Kraenzl) N.Tanaka, 2001 - widespread in South and Southeast Asia, where it is supposed to have differentiated within the past few centuries.
The species prefers light (sandy), medium (loamy) and heavy (clay) soils and requires well-drained soil. The preferred soil is acid, neutral and basic (alkaline). It cannot grow in the shade and requires moist soil.
- Kew World Checklist of Selected Plant Families, Canna glauca
- Johnson's Gardner's Dictionary (1856)
- Tanaka, N. 2001. Taxonomic revision of the family Cannaceae in the New World and Asia. Makinoa ser. 2, 1:34–43.
- Cooke, Ian, 2001. The Gardener's Guide to Growing cannas, Timber Press. ISBN 0-88192-513-6