Yellow Flag, Iris pseudacoris, Naturalized Minnesota Wildflower plant, Eloise Butler Wildflower Garden, Invasive

	Plants of the Eloise Butler Wildflower Garden
	Common Name	Scientific Name	Plant Family	Garden Location	Prime Season
	Yellow Flag Iris	Iris pseudacorus L.	Iris	Woodland - bog	Early summer
Other names and notes	(Pale Yellow Iris), A plant of marshes and wet meadows, it is similar to the Blue Flag Iris; the plant grows 1 to 3 feet high with yellow flowers about 4 inches wide, 2 to 3 flowers on one round leafless stalk. The flower stalk is shorter that the outer leaves as the large photo below shows. Under each flower is a solitary bract. The drooping sepals, which surround the true flower, can vary in color, pale yellow being most common, and generally curve outward, have short claws and are usually purple veined as the photos show. The petals are smaller than the sepals and curve upward. The style in the center has three petal like branches. Seed capsules have three chambers with two rows of seeds, which turn dark brown at maturity. The plant spreads via stout rhizomes; it forms clumps as the rhizomes separate. Leaves are sword shaped, 20 to 40" long, with a raised mid-rid. Blooms are usually the last half of June.

Notes: Yellow Flag is not native (native to Eurasia) and is an escapee from cultivation. In Minnesota it is considered invasive and is being considered for regulation as an exotic species. It has been collected in only 4 counties in the state, Hennepin included. In North America is has been naturalized in also all the lower states and Canadian Provinces with exceptions mainly in the Great Plains. Martha Crone listed it on her 1951 Garden Census and it has been in the Garden ever since.

Uses and Lore: Yellow Flag can grow in soils with pH ranging from 3.6 to 7.7 and tolerates low oxygen, can absorb metals and lives in areas of high levels of soluble organics. USDA Reports that the plant may be able to remove heavy metals efficiently and economically from wastewater. It is unpalatable to livestock due to levels of glycoside in the leaves. The plant grows along the river Lys in Flanders and due to this presence the French-Canadian botanist considered it to be the original model for the fleur-de-lis of French heraldry. French chemists in the 19th century discovered that the ripe seeds, when roasted, make a good coffee substitute. (Refs W2 and 31)

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References: Plant characteristics are generally from sources 15, 16, 30, 31, 33, W2 & W3. Distribution principally from W2 and also 31, 34 and W1. Planting history generally from 1, 4 & 4a. Other sources by specific reference. See Reference List for details.

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