Home/Species/ Dwarf Lake Iris

Iris lacustris

Nutt.

Dwarf Lake Iris

G3Vulnerable Found in 2 roadless areas NatureServe Explorer →

G3VulnerableGlobal Rank

Near threatenedIUCN

Identity

Unique IDELEMENT_GLOBAL.2.149152

Element CodePMIRI090H0

Record TypeSPECIES

ClassificationSpecies

Classification StatusStandard

Name CategoryVascular Plant

IUCNNear threatened

Endemicoccurs (regularly, as a native taxon) in multiple nations

KingdomPlantae

PhylumAnthophyta

ClassMonocotyledoneae

OrderLiliales

FamilyIridaceae

GenusIris

Other Common Names

dwarf lake iris (EN) Iris lacustre (FR)

Concept Reference

Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.

Conservation Status

Rank MethodLegacy Rank calculation - Excel v3.1x

Review Date2014-02-03

Change Date1984-12-10

Edition Date2014-02-03

Edition AuthorsDoyle, K.

Range Extent5000-20,000 square km (about 2000-8000 square miles)

Number of Occurrences81 - 300

Rank Reasons

Endemic to the Great lakes region: Michigan, Wisconsin, and Ontario. Within this limited geographical range, the species is occasionally locally abundant, occuring semi-continuously for several km along the northern shores of Lakes Huron and Michigan. Shoreline development is the most significant threat to the species. Off-road vehicle use, road widening, chemical spraying and salting, invasive species and natural plant succession are lesser threats.

Range Extent Comments

Almost exclusively found on the northern shores of Lakes Michigan, Huron and Superior. Approximate range extent is 4100 sq miles.

Occurrences Comments

Approximately 162 extant occurrences in WI, MI and ON.

Threat Impact Comments

Shoreline development remains the biggest threat to Iris lacustris although many of EOs are on public land and therefore protected from such development. Additional threats include off-road vehicle traffic, invasive species and natural plant succession. Climate change will almost certainly have a negative effect on this species. There are other disturbances such as road maintenance that are not entirely negative.

Ecology & Habitat

Habitat

Thrives best in close proximity to the northern Great Lakes shores, where it is most often found in young, well-drained soils ranging from sands to gravels to sandy clay loam and organic-enriched sands. Distributional and field data demonstrate that it achieves its best growth in calcareous environments. While it has been found in full sun and nearly complete shade, optimal sexual reproduction appears to occur in partially shaded or sheltered forest edges. It is most often associated with coniferous forest dominated by northern white-cedar (Thuja occidentalis) and balsam fir (Abies balsamea). Old beach ridges associated with post-glacial shorelines, many occurring significant distances inland from current lake shores, provide similar habitat that often supports the species, but in many of these inland sites the species persists mostly as sterile colonies, slowly senescing under the shade of more mature overstory vegetation.

Terrestrial Habitats

Forest/WoodlandForest - ConiferForest Edge

Other Nations (2)

CanadaN3

Province	Rank	Native
Ontario	S3	Yes

United StatesN3

Province	Rank	Native
Michigan	S3	Yes
Wisconsin	S3	Yes

Threat Assessments

Threat	Scope	Severity	Timing
1 - Residential & commercial development	Large (31-70%)	Serious or 31-70% pop. decline	High - moderate
4 - Transportation & service corridors	Large - restricted	Moderate or 11-30% pop. decline	High - moderate
4.1 - Roads & railroads	Large - restricted	Moderate or 11-30% pop. decline	High - moderate
6 - Human intrusions & disturbance	Large - restricted	Moderate or 11-30% pop. decline	High (continuing)
6.1 - Recreational activities	Large - restricted	Moderate or 11-30% pop. decline	High (continuing)
8 - Invasive & other problematic species, genes & diseases	Large - restricted	Moderate or 11-30% pop. decline	High (continuing)

Plant Characteristics

Economic Value (Genus)No

Roadless Areas (2)

Michigan (2)

Area	Forest	Acres
Government Island	Hiawatha National Forest	225
Round Island	Hiawatha National Forest	2

References (29)

Alverson, W. 1981. Bull. Botanical Club of Wisconsin 13(3): supplement.
Argus, G.W., and D.J. White, eds. 1982. Atlas of the rare vascular plants of Ontario. Part 1. National Museum Natural Science, Ottawa.
Atwood, W.H. 1933. The lake iris and its differentiation from cristata. Bull. Am. Iris Soc. 47:78-79.
Braker, Nancy. Former Director of Stewardship and Registry, Wisconsin Field Office, The Nature Conservancy.
Braun, L.E. 1967. The Monocotyledoneae: cat-tails to orchids. Vol. One. Ohio State Univ. Press, Columbus, Ohio. 464 pp.
Crispin, S., and M. Penskar. 1990. Iris lacustris. Unpublished abstracts for Michigan Natural Features Inventory, Endangered Species Manual.
Ewert, D. Land Steward, Michigan Field Office, The Nature Conservancy. Personal communication.
Flora of North America Editorial Committee (FNA). 2002a. Flora of North America north of Mexico. Vol. 26. Magnoliophyta: Liliidae: Liliales and Orchidales. Oxford Univ. Press, New York. xxvi + 723 pp.
Foster, R.C. 1937. A cytotaxonomic survey of the North American species of Iris. Contr. Gray Herb. 119. 82pp.
Guire, K.E., and E.G. Voss. 1963. Distributions of distinctive shoreline plants in the Great Lakes Region. Michigan Botanist 2: 99-114.
Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
Litzow, M. 1978. Iris lacustris Nutt: Summary of the literature by Margaret Litzow. Unpublished report to the Minnesota Landscape Arboretum, Chanhassen, MN. 6pp.
Makholm, M.M. 1986. Ecology and management of Iris lacustris in Wisconsin, M.S. thesis, University of Wisconsin, Madison. 122 pp.
Mohlenbrock, R.H. 1983. Where have all the wildflowers gone? A region-by-region guide to threatened or endangered U.S. wildflowers. Macmillan Publishing Co. Inc., New York. 239 pp.
Morgan, M. 1990. Professor of Botany, University of Wisconsin, Green Bay.
Oldham, Michael. Personal communication. Botanist, Ontario Natural Heritage Information Centre.
Penskar, Mike. Personal communication. Botanist, Michigan Natural Features Inventory. Lansing, MI.
Planisek, S. L. 1983. The breeding system, fecundity, and dispersal of <i>Iris lacustris</i>. The Michigan Botanist 22: 93-102.
Randall, C. 1978. Four threatened plants for the Great Lakes shorelines. Michigan Department of Natural Resources report, Lansing. 6pp.
Read, R.H. 1976. Endangered and threatened vascular plants of Wisconsin. Technical Bull. No. 92, Scientific Areas Preservation Council, Dept. Natural Resources, Madison, WI. 58 pp.
Rees, M.D. 1988. Final listing rules approved for 25 species. Endangered Species Tech. Bull. 13(9-10): 3-5.
Slaughter, Bradford. Botanist, Michigan Natural Features Inventory, Lansing, MI.
Stebbins, G.L. 1935. Some observations on the flora of the Bruce Peninsula, Ontario. Rhodora 37:63-74.
Trick, J.A., and G. Fewless. 1984. A new station for dwarf lake iris. Michigan Botanist 23: 68.
U.S. Fish and Wildlife Service (USFWS). 1976. Endangered Species Technical Bull. July 1976.
U.S. Fish and Wildlife Service (USFWS). 1988. Habitat loss threatens two midwestern plants. Endangered Species Tech. Bull. 13(1):1.
U.S. Fish and Wildlife Service (USFWS). No date. Unpublished draft recovery plan for dwarf lake iris (Iris lacustris). U.S. Fish and Wildlife Service Recovery Team, Twin Cities, Minnesota.
van Kley, J.E. 1988. Habitat and ecology of Iris lacustris (the dwarf lake iris). M.S. thesis. Central Michigan University, Mount Pleasant. 82 pp.
Waller, A.E. 1931. The native Iris of Ohio and bordering territory. Ohio. J. Sci. 31: 29-43.

Iris lacustris

Habitat

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