Dwarf Lake Iris
Scientific Name: Iris lacustris
Taxonomy Group: Vascular Plants
Last COSEWIC Assessment: November 2010
Last COSEWIC Designation: Special Concern
SARA Status: Schedule 1, Threatened
Image of Dwarf Lake Iris
The Dwarf Lake Iris is a small iris that can grow to a height of approximately 10 cm. It was once considered a subspecies of Iris cristata because it is similar to this species, only smaller. The narrow, arching leaves, which are about 6 cm long during the flowering period, can grow to 18 cm by the end of the season. The highly visible flowers have a diameter of 3 to 5 cm. Flowers are typically blue, although there is a variety that produces white flowers. This species reproduces mainly vegetatively through its rhizomes (underground horizontal stems). The tip of each rhizome is enlarged and produces two leaves that form a sheath around a stem that will eventually flower. This allows the species to establish very large colonies.
Distribution and Population
The Dwarf Lake Iris is native to the Great Lakes region. It occurs mainly on the north shores of Lake Michigan and Lake Huron, and in a few inland sites slightly to the north. In the United States, the species has been documented in 60 sites in Michigan and 15 sites in Wisconsin. In Canada, the Dwarf Lake Iris occurs in Ontario from the western shore of the Bruce Peninsula to the south shore of Manitoulin Island, in the northern part of Lake Huron. This species has been observed in 43 sites in Ontario. In 2003, 32 of the accessible sites were visited and the presence of the Dwarf Lake Iris was confirmed in 16 of these sites. Two other sites were discovered and it is likely that the species still occurs in three of the sites that were not visited. The Canadian population is estimated to number just under one million shoots. It is difficult to determine trends for the various populations since this species has never been systematically surveyed before. While the number of sites has declined over the last hundred years, the extent of the decline is not known.
The Dwarf Lake Iris grows on ridges of sandy or gravelly beaches near the north shore of Lake Huron. This species grows in shallow, calcareous and well-drained soil in areas where there are openings in the forest canopy. It is typically found in Eastern White Cedar or Balsam Fir forests. Although this tiny iris can tolerate a multitude of microclimates, it grows best in semi-shaded areas where the water table is just below the surface of the soil.
The Dwarf Lake Iris is a perennial species. In the fall, the exposed part of the plant dies and the rhizomes remain dormant through the winter. In the spring, new shoots emerge from these underground stems. In Ontario, the plants flower from mid-May to early June and insects pollinate the flowers, which remain open for about three days. While a flower can be fertilized with its own pollen, this is less conducive to the development of fruit. The seeds are disseminated by ants and germinate sporadically after lying dormant over extended periods of time. This species mainly reproduces vegetatively through the development of its rhizomes.
Considering that the factors to which the Dwarf Lake Iris is most sensitive are light and the level of the water table, any change to the forest canopy or the water regime could have an impact on this species. In Ontario, the biggest threat to this species is the construction of cottages along the highly coveted shores of Lake Huron. There has been a great deal of recent development in this area and many undeveloped lots are up for sale.
Federal ProtectionMore information about SARA, including how it protects individual species, is available in the Species at Risk Act: A Guide.
The Dwarf Lake Iris is not protected under any provincial law in Ontario. However, the Dwarf Lake Iris in Bruce Peninsula National Park is protected by the Canada National Parks Act. This species also occurs in MacGregor Point Provincial Park, where it is afforded a certain degree of protection.
Provincial and Territorial Protection
Status of Recovery Planning
Recovery Strategies :
Name Recovery Strategy for the Dwarf Lake Iris (Iris lacustris) in Canada
Status Final posting on SAR registry
Recovery Progress and Activities
Summary of Progress to Date Recovery for the Dwarf Lake Iris will be addressed by the National Recovery Strategy produced by the recovery team for this plant. A recovery team was established in July 2007. Summary of Research/Monitoring Activities Population inventory work is taking place on both Manitoulin Island and the Bruce Peninsula. Parks Canada initiated a detailed inventory on Manitoulin Island in 2006 and will be continuing this inventory on both Manitoulin Island as well as at Bruce Peninsula National Park in 2007. Habitat mapping is being completed as part of these inventories. The Ontario Ministry of Natural Resources invites the public to report sightings of rare species, including the Dwarf Lake Iris, on their website. Summary of Recovery Activities Several key alvars have been protected in the last 10 years, some of which are habitat for the Dwarf Lake Iris. An alvar is an ecosystem found on a limestone plain with thin or no soil, consists of sparse vegetation, and supports many species at risk. Site ranking exercises have been recently completed for both the Bruce Peninsula and Manitoulin Island in order to prioritize areas for conservation and protection. These rankings help guide stewardship activities. At Bruce Peninsula National Park management has focused on maintaining the integrity of alvar habitat. This has included routing trails away from sensitive areas and construction of boardwalks. An atlas focusing on important conservation areas in the Bruce Peninsula, such as alvar habitat with Dwarf Lake Iris, was developed in November 2005 by the Wilderness League Chapter of the Canadian Parks and Wilderness Society, in partnership with many other organizations. This atlas has been distributed to industry developers and is available to the public on the internet. A considerable amount of public contact and education about alvars is taking place, mostly due to the International Alvar Initiative (IACI). Contact was made with hundreds of alvar landowners when permission was sought to survey their lands for the IACI. This was followed up with stewardship packages given to many of these landowners. Through this effort, the word "alvar" has become a familiar term in common usage in the Bruce Peninsula and Manitoulin Island region. Various media publicized alvars during the IACI’s Alvar Workshop in June 1998. The Nature Conservancy Canada, the Federation of Ontario Naturalists, and The Nature Conservancy – Great Lakes Program have featured alvars in their publications and on their web sites. For those areas where Dwarf Lake Iris exists and is not associated with alvar ecosystems, recovery priorities will be identified in the recovery strategy. URLs: Ontario Ministry of Natural Resources: Natural Heritage Information Centre Fact sheet:http://nhic.mnr.gov.on.ca/MNR/nhic/documents/brochure.pdf Ontario Biodiversity: Species at Riskhttp://www.rom.on.ca/ontario/risk.php?doc_type=fact&lang=&id=290 Ontario Ministry of Natural Resources: Natural Heritage Information Centre: Rare Species Sightings Reports:http://nhic.mnr.gov.on.ca/MNR/nhic/species/species_report.cfm Canadian Parks and Wilderness Society: Bruce Peninsula Atlas: (available for download)http://www.cpaws.org/community-atlas/bruce.php
PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.
14 record(s) found.
- COSEWIC Status Reports (1 record(s) found.)
- COSEWIC Assessments (1 record(s) found.)
- Response Statements (2 record(s) found.)
- Recovery Strategies (1 record(s) found.)
- Action Plans (1 record(s) found.)
- Orders (4 record(s) found.)
- COSEWIC Annual Reports (2 record(s) found.)
- Consultation Documents (2 record(s) found.)
COSEWIC Status Reports
COSEWIC Annual Reports
COSEWIC Annual Report - 2005 (2005)2005 Annual Report to the Canadian Endangered Species Conservation Council (CESCC) from the Committee on the Status of Endangered Wildlife in Canada.
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