Plants of the Eloise Butler Wildflower Garden

Blue Flag is a plant of marshes and wet meadows, growing 1 to 3 feet high on solid stems.

Leaves are sword shaped, 20 to 40 inches long, green to grayish-green color and prominently veined, with a raised (thickened) mid-rid in mature leaves. As basal leaves, they rise from the root in a fan shape, erect, and then later drooping. The flower stem may also have a few leaves and these are usually short and do not rise above the flower stalk.

The inflorescence consists of 2 to 4 flowers, that are similar to many beardless iris, at the top of a solid stem that rises from the root. Stems may branch once and may have some stem leaves. The upper section of the stem under each flower forms a spathe covering the ovary of the flower. Bloom time is the end of May to the end of June in this part of Minnesota depending on the season's weather.

Flowers are blue to purple (are rarely white), about 4 inches wide. The three outer ovate violet-blue sepals spread outward; the base narrows abruptly with a hairy greenish or yellowish patch surrounded by white, lined with purple veins - this area being known as a 'signal'. The Garden plants have a yellow spot. Very showy. The petals (often called 'standards' in the Iris genus) are the same color but are oblong, much shorter that the sepals, have smooth margins and are upright. The fruiting parts are in the center of the flower. The styles form flat arms, with curled tips and smooth margins, which reflex outward and lie atop the base of the sepals with the anthers and stigma hidden from view between the two protecting the pollen from rain. The nectar of the plant is in glands at the base of the petals.

Fruit: The seed forms in a somewhat 3-sided cylindrical capsule, each side has 2 rows of seeds which are thin, D-shaped, and hard (not corky like I. pseudacorus). These capsules often overwinter. Seeds are distributed by wind when the capsule opens. These seeds require at least 120 days of cold stratification for germination and are thus best propagated by sowing outside in the fall.

Habitat: The root stock is a branching rhizome with fleshy roots. Branches are the same size and texture as the main rhizome (said to be 'homogeneous'). Propagation is by seed or single rhizomes cut from the main root stock. The plant will spread vegetatively to form large clumps if left undisturbed. While the plant has few pests or diseases, it can be overgrown by more aggressive plants. However, in wet grazing meadows it may be weedy as grazing animals will not eat it but do eat its competitors. I. versicolor requires a wet meadow or marshy area with full sun to grow best.

Names: The genus name, Iris, is after the Greek goddess of the rainbow. The species, versicolor, means 'variously colored'. The author name for the plant classification, 'L.' is for Carl Linnaeus (1707-1778), Swedish botanist and the developer of the binomial nomenclature of modern taxonomy.

Comparison: The other iris in the Garden wetland is Yellow Flag Iris, Iris pseudacorus L. This is a non-native iris considered to be an invasive species, but has been allowed to exist in the Garden under control. Of closer resemblance is I. virginica, the Southern Blue Flag where the only visual difference is that the signal area is a pubescent yellow only without the yellow patch being surrounded by the purple-on-white veined area.