Endangered Plants of Ontario

Dwarf Lake Iris

Iris Lacustris

Status

Rare in Canada; extirpated from Connecticut, endangered in Iowa and New Jersey, rare in Maryland, Michigan, Mississippi, Vermont, and Wisconsin.

Range

Shorelines of Lakes Huron and Michigan; native only to the shores of the middle Great Lakes.

Habitat

Old dunes, sandy coniferous woods, and in shallow soil over

limestone.

Height

5 to 8 cm.

Bloom Period

Late May and early June.

Factors contributing to its status

Dwarf lake iris has never been abundant. It grows in thick patches in its particular habitat, but this habitat is restricted to the areas immediately adjacent to the middle Great Lakes.

This species is threatened by loss of habitat due to shoreline development -- most of its range lies in the popular summer cottage areas. A good assessment of its abundance is needed, along with strong protective regulations against development of the areas in which it grows

Notes

Dwarf lake iris produces rhizomes on or just below the soil surface that can form extensive clonal patches. The pollen from a flower can fertilize the ovules (potential seeds) in the same flower or in another flower in the same patch, but an insect visit is necessary for pollen transfer to occur, and seed set is generally low. The seeds are dispersed by ants, which take the seeds to their nests, remove a seed appendage that they find edible, then discard the rest of the seed intact some distance from the nest. The seeds of Ontario's floral emblem, white trillium, are dispersed in the same way.

Habitat	Old dunes, sandy coniferous woods, and in shallow soil over limestone.
Height	5 to 8 cm.
Bloom Period	Late May and early June.
Factors contributing to its status	Dwarf lake iris has never been abundant. It grows in thick patches in its particular habitat, but this habitat is restricted to the areas immediately adjacent to the middle Great Lakes. This species is threatened by loss of habitat due to shoreline development -- most of its range lies in the popular summer cottage areas. A good assessment of its abundance is needed, along with strong protective regulations against development of the areas in which it grows
Notes	Dwarf lake iris produces rhizomes on or just below the soil surface that can form extensive clonal patches. The pollen from a flower can fertilize the ovules (potential seeds) in the same flower or in another flower in the same patch, but an insect visit is necessary for pollen transfer to occur, and seed set is generally low. The seeds are dispersed by ants, which take the seeds to their nests, remove a seed appendage that they find edible, then discard the rest of the seed intact some distance from the nest. The seeds of Ontario's floral emblem, white trillium, are dispersed in the same way.