Wildflowers of the Adirondacks:
Blue Flag (Iris versicolor)

Wildflowers of the Adirondack Park: Blue Flag on the edges of Heron Marsh (13 June 2015).
Wildflowers of the Adirondacks: Blue Flag's sword-like leaves emerge from thick horizontal root stock. Blue Flag on the edges of Heron Marsh (13 June 2015).

Blue Flag (Iris versicolor) is a native iris that grows in wetlands in the Adirondack Mountains of upstate New York. It produces showy violet-blue flowers in early summer.

This plant is also called Northern Blue Flag, Larger Blue Flag, Harlequin Blueflag, and Wild Iris. The name flag is from the middle English word "flagge," meaning rush or reed. Iris flowers are said to symbolize power, with the three parts representing wisdom, faith and courage.


Identification of the Blue Flag

Wildflowers of the Adirondack Park: Blue Flag on Heron Marsh (18 July 2013).
Wildflowers of the Adirondacks: Blue Flag produces showy violet-blue flowers in early summer. Blue Flag blooming on the edges of Heron Marsh (18 July 2013).

Blue Flag grows about 2-3 feet tall with long, narrow leaves (1/2 to 1 inch wide) of bluish green. It produces several striking, violet-blue flowers. The down-curved violet sepals are veined in yellow and white. The flowers are 2.5 to 4 inches wide.

Blue Flag flowers in early summer in the Adirondacks. A tally of flowering dates for the upland Adirondack areas compiled by Michael Kudish, based on data collected from the early seventies to the early nineties, lists 16 June as the earliest date of flowering and 27 June as the median date. More recently, Blue Flag has been blooming somewhat earlier.

Blue Flag plants are pollinated by bees and, like other plant species pollinated by bees, have evolved special types of flowers that are easy for bees to find. Blue Flag has large lobes that bees use as landing platforms and special markings directing bees to the nectar glands.

Uses of Blue Flag

In the past, Blue Flag was a popular medicinal plant among North American Indian tribes. Although Blue Flag is poisonous, Native Americans and colonists dried the rhizome of the plant and used it in small amounts as a cathartic and diuretic. In addition, some North American Indian tribes reportedly used the two outermost fibers of the leaves to spin twine. Powdered iris root has also been added to perfume and potpourri.

Wildlife Value of Blue Flag

Blue Flag has limited value as a food source for wildlife. Several non-pollinating nectar feeders are frequent flower visitors, including Harris Checkerspot and Hobomok Skipper. Blue Flag also attracts bees and hummingbirds.

Distribution of Blue Flag

The native distribution of Blue Flag includes the northeastern part of the US, south to Virginia. In Canada, its distribution spans from Newfoundland to Manitoba. 

In New York State, Blue Flag is found in nearly all counties in the eastern part of the state. It has been documented growing in all counties within the Adirondack Park Blue Line.

Habitat of Blue Flag

Blue Flag grows in poorly drained soils and the shallow water on the edges of marshes.  It is shade intolerant.  It will tolerate water to a depth of one to two feet. This plant is abundant in several ecological communities in the Adirondack Park:

One of the most convenient places to study this plant is Heron Marsh at the Paul Smiths VIC. It grows on the edges of the marsh, together with cattails and sedges. Listen for a chorus of amphibians that breed on shallow emergent marshes, including Northern Spring Peeper, Green Frog, and Wood Frog. Birds commonly seen flitting about Blue Flag plants include Swamp Sparrow, Common Yellowthroat, and Red-winged Blackbird.


References

Michael Kudish. Adirondack Upland Flora: An Ecological Perspective (The Chauncy Press, 1992), pp. 23-28, 233.

New York Flora Association.  New York Flora Atlas. Blue Flag. Iris versicolor L.
Retrieved 18 March 2017.

United States Department of Agriculture. The Plants Database. Harlequin Blueflag. Iris versicolor L. Retrieved 18 March 2017.

United States Department of Agriculture. NRCS National Plant Data Center & the Biota of North America Program. Plant Fact Sheet. Blue Flag. Retrieved 18 March 2017.

Flora of North America. Blue Flag.  Retrieved 18 March 2017.  

New York State. Department of Environmental Conservation. New York Natural Heritage Program. Ecological Communities of New York State. Second Edition (March 2014), pp. 48-49.  Retrieved 17 October 2015.

New York Natural Heritage Program. 2015. Online Conservation Guide for Medium Fen. Retrieved 14 March 2017.

New York Natural Heritage Program. 2015. Online Conservation Guide for Rich Shrub Fen. Retrieved 14 March 2017.

New York Natural Heritage Program. 2015. Online Conservation Guide for Rich Graminoid Fen. Retrieved 14 March 2017.

New York Natural Heritage Program. 2015.  Online Conservation Guide for Shallow Emergent Marsh. Retrieved 22 February 2017.

New York Natural Heritage Program. 2015.  Online Conservation Guide for Silver Maple-Ash Swamp.  Retrieved 6 March 2017.

New York State. Adirondack Park Agency. Preliminary List of Species Native Within the Adirondack Park Listed Alphabetically by Scientific Name and Sorted by Habit. Volume 1. Updated 10.23.2006. Retrieved 26 January 2017.

John Eastman. The Book of Swamp and Bog: Trees, Shrubs, and Wildflowers of Eastern Freshwater Wetlands (Stackpole Books, 1995).

Lady Bird Johnson Wildflower Center. Native Plant Database.

Plants for a Future. Database.

University of Michigan. Native American Ethnobotany. A Database of Foods, Drugs, Dyes and Fibers of Native American Peoples, Derived from Plants.  Iris versicolor L. Harlequin Blueflag.  Retrieved 18 March 2017.

Anne McGrath. Wildflowers of the Adirondacks (EarthWords, 2000), pp. 60, 89.

Doug Ladd. North Woods Wildflowers (Falcon Publishing, 2001), p. 47.

Lawrence Newcomb. Newcomb's Wildflower Guide (Little Brown and Company, 1977), pp. 120-121.

Roger Tory Peterson and Margaret McKenny. A Field Guide to Wildflowers. Northeastern and North-central North America (Houghton Mifflin Company, 1968) pp. 314-315.

Donald D. Cox. A Naturalist's Guide to Wetland Plants. An Ecology for Eastern North America (Syracuse University Press, 2002), pp. 53-54.

William K. Chapman, et al. Wildflowers of New York in Color (Syracuse University Press, 1998), pp. 122-123.

National Audubon Society. Field Guide to Wildflowers. Eastern Region. (Alfred A. Knopf, 2001), pp. 571-572, 611.

Wildflowers of the Adirondack Park


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