Search / Plant Profile / Iris lacustris

Plant Profile

Dwarf lake Iris (Iris lacustris)

This species occurs only on the northern shores of the Great Lakes and in a few openings in cedar/birch forests, as shown here in Door County, Wisconsin. Photo Credit: WI DNR

Global Rank: G3 - Vulnerable
Legal Status: Federally Threatened
Family: Iridaceae
State: CAN, MI, ON, WI
Nature Serve ID: 149152
Lifeform: Forb/herb
Date Inducted in National Collection: 03/14/1986

Description:

This miniature perennial iris has deep blue, sometimes lilac or white flowers (1 1/2 inches in width and 1 1/2-2 1/2 inches in height) that occur one flower per stem. Flowers appear from early May to early June, and have 3 petals with yellow crests. Stems are less than 2 inches tall. Leaves are 6 inches long and 1/2 inch wide. They are flattened, sword shaped, and come in fan shaped clusters. Although globally rare, this species can reproduce clonally from rhizomes, so where it is found it grows in thick patches. The species is self-compatible, but insects are needed to transport the pollen, and seed set is generally low. The few seeds produced are dispersed by ants.

Where is Dwarf lake Iris (Iris lacustris) located in the wild?

Habitat:

Found on the north shores of the Great Lakes, this species generally occurs near to the lakes' shorelines, as it is well adapted to the cool, moist lakeshore air there. Intolerant of full sun, you often find this species growing in sandy or gravelly soil in the partial shade of coniferous trees or the mesic areas at a forest's edge. (USFWS 1988)

Distribution:

Around the Great Lakes; near the Northern Shores of Lake Huron and Lake Michigan, in Michigan. Found in the states of: Wisconsin, Ohio, Michigan, and the province of Ontario (USFWS 1988).

States & Provinces:

Dwarf lake Iris can be found in Canada, Michigan, Ontario, Wisconsin

Which CPC Partners conserve Dwarf lake Iris (Iris lacustris)?

Holden Forests and Gardens

Conservation Actions

10/11/2020

Dr. Gary L. Hannan, at Eastern Michigan University, has studied the reproductive biology and genetic diversity of this species. He found that I. Lacustris has very little genetic diversity compared to its more widespread relative, Iris cristata.

10/11/2020

Dawn M. Gerlica and Lindsey Parsons

01/01/2010

Residential and shoreline development Road construction Recreational activities Chemical spraying Road salting Habitat succession Off-road vehicles (ORV's) Being sold as a commercial flower Picking (generally results in the flower being uprooted)

Dawn M. Gerlica and Lindsey Parsons

01/01/2010

At the time of federal listing in 1988, this species was found in about 60 sites in 10 counties on the northern shores of Lake Michigan and Huron. (USFWS 1988) Ninety five percent of the known populations of this species occur in Michigan (Chittenden & Carrington 1996).

Dawn M. Gerlica and Lindsey Parsons

01/01/2010

Dawn M. Gerlica and Lindsey Parsons

01/01/2010

None known.