Canna glauca comes from the wetlands of tropical America, and its adaptations to that origin are visible in every part of the plant. The leaves are unusually narrow for the genus — up to eighteen inches long but slender — and their distinctive blue-green color, referenced in the species name glauca, sets it apart from the broader-leaved, more flamboyantly colored cannas. The flowers are pale yellow and relatively small by canna standards, opening in clusters at the stem ends through summer and into fall, modest and lovely where other species announce themselves more loudly.

Its tolerance of genuinely wet conditions is unusual and useful: water canna can be grown in shallow still or slow-moving water up to six inches deep during summer, making it one of the few ornamental perennials that functions equally well as a marginal aquatic and as a border plant. It grows four to six feet tall and asks for full sun or partial shade and organically rich soil. In warmer zones, the rhizomes can overwinter in the ground with a mulch cover after the foliage is cut back; in colder areas, lift and store them in peat or vermiculite at 45 to 50 degrees F. Deadheading spent blooms extends the flowering season noticeably.