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U.S. Forest Service

Our Native Irises: Blue Flag Irises

Iris tridentata: Savannah Iris

Savannah iris occurs from North Carolina to Florida on the coastal plain and in the Tennessee interior.

Iris tridentata. This view of Iris tridentata shows the much reduced petals that are barely developed in this species as is with Iris setosa. Photo by Dr. Jean Everett, College of Charleston.

Map of the range of Iris tridentata in North America. Range map of Iris tridentata. Courtesy of the USDA PLANTS Database.

Iris tridentata flowers are purple-blue. The sepals are widely spreading and then arching downward with prominent dark purple veins and a white to yellow signal. The petals are greatly reduced, not exceeding the base of the sepals. The inflorescence is one-flowered, the flowering stalk taller than the attending leaves. The leaves are bright green, basal and upright, from extensively branched, wandering rhizomes, rooting at the nodes and forming loose colonies.

Iris tridentata is found growing in shaded, rich, swamps and wetlands in the coastal plain with an interior disjunct population in Tennessee.

Iris tridentata. The dark purple veins and the yellow signal of Iris tridentata serve as the nectar guides for pollinating bumblebees. Photo by Dr. Jean Everett, College of Charleston.

Iris tridentata habitat. Iris tridentata occurs commonly in pitcher plant communities. Photo by Collette Degarady, The Nature Conservancy.

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