Southern blue flag, or Virginia iris, is a herbaceous perennials growing from rhizomes.
The flowers grow near the top of the stems. The 3 sepals are descriptively called “falls”; the 3 upright petals are the “standards.” The flower color varies from nearly white to deep violet, sometimes in a veined pattern. Blooms May–July.
The leaves are mostly basal, straplike, to over 2 feet long, folded along the midrib.
Similar species: Eleven Iris species have been recorded growing out of cultivation in our state; seven are nonnative and four are native. This is the most common of the four that are native to Missouri. To learn more about the irises you might encounter in Missouri's habitats, see their group page.
Height: to 3 feet.
Scattered statewide; principally in northern and central Missouri.
Habitat and Conservation
Occurs in a wide variety of wetland sites, including marshes, wet meadows, swamps, river bottoms, sloughs, ditches, bottomland prairies, edges of sinkhole ponds, and in shallow water.
As a native garden subject, this iris needs full sun and a wetland situation, making it especially good for water gardening. Of our four native irises, this has the widest distribution.
Status
Native Missouri wildflower.
Human Connections
When people make changes to river channels and alter natural patterns of water drainage, it causes habitat loss for this species, reducing its populations.
Irises have had a long history in cultivation — as ornamentals, for perfumery and culinary flavoring, and for medicinal uses — even dating back to ancient Egypt.
There have been reports of some people developing a mild skin rash after handling irises.
Ecosystem Connections
Bumblebees collect nectar from irises, cross-pollinating them in the process.
Few mammals eat this species because the plant irritates the digestive tract.
As with other plants that colonize wetlands, they play an important role in cleaning water and stabilizing soils.
