Blue flag: A Bit of Botany
a little botanical information about blue flag

Blue flag, an herbaceous perennial of the ridaceae family, resembles a common garden iris and is often confused with Sweet Flag, which is another plant in another genus.

Blue flag is a marginal aquatic plant that forms a clump of narrow, arching-to-erect, sword-shaped, blue-green leaves (to 24" long and 1" wide). Flowering stalks rise from the clump to 30" tall in late spring, typically producing 3-5 violet-blue flowers per stalk. Flowers have white and yellow markings at the sepal bases. Clumps spread slowly and naturalize by tough, creeping rhizomes.

common names & nomenclature
In Greek mythology Iris—Greek for "rainbow"—was the goddess of the rainbow and messenger of the gods. While versicolor, which means "having many colors" is in allusion to the prismatic colors of the species.

Also known as:
flag-lily, fleur-de-lis, flower-de-luce, iris, liver lily, wild iris, poison flag, flag lily, snake lily, dragon flower, dagger flower, water flag, harlequin blueflag, larger blue flag, northern blue flag

Blue Flag, the water-loving root flower
Blue flag: Where in the World
habitat and range for blue flag

Iris versicolor is native to North America. It grows from Manitoba to Nova Scotia south to Virginia, Ohio, Illinois and Minnesota.

Blue flag: Cultivation & Harvesting
considerations for growing and harvesting blue flag

Blue flag grows in sedge meadows, marshes, and along stream banks and shores in full sun to part shade.

Grows in medium to wet soils, can be grown in shallow standing water.

Propagate by division after the plant blooms. Wear gloves when dividing the rhizomes as sap may irritate skin. After fall frost, the plant leaves may be trimmed back to about 1" above the crown. Blue flag will naturalize to form colonies in the wild.

If planted in August or September, it can be harvested at the end of October the following year. Wear gloves to dig out rhizomes, shake of excess soil, wash if needed, allow to dry completely.

Once dried all the way through, the rhizome can then be cut into small pieces. Store in a cool, dry place in an airtight container.

The fresh rhizome of Blue Flag is poisonous. Gloves are necessary for harvesting. Do not ingest fresh rhizome.

Blue flag: The Rest of the Story
blue flag history, folklore, literature & more

Blue flag, or Iris versicolor, is a perennial wild iris indigenous to eastern North America named after the Greek goddess of the rainbow. The plant looks very similar to the common garden-variety iris except that the flowers, which are a vivid bright blue, are slightly smaller.

Blue flag is known by many other common names that reflect its historical significance. Since early European settlers thought the plant closely resembled its European cousin, which inspired the design of the official emblem of French royalty, blue flag is sometimes called fleur-de-lis. Other common names include snake lily and water lily, a reference to the plant’s ability to thrive in shallow water.