Iris lacustris
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''Iris lacustris'', the dwarf lake iris, is a plant species in the genus ''
Iris Iris most often refers to: *Iris (anatomy), part of the eye *Iris (mythology), a Greek goddess * ''Iris'' (plant), a genus of flowering plants * Iris (color), an ambiguous color term Iris or IRIS may also refer to: Arts and media Fictional ent ...
'', subgenus '' Limniris'' and in the section ''Lophiris'' (crested irises). It is a
rhizomatous In botany and dendrology, a rhizome (; , ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow ho ...
, beardless
perennial plant A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...
,
native Native may refer to: People * Jus soli, citizenship by right of birth * Indigenous peoples, peoples with a set of specific rights based on their historical ties to a particular territory ** Native Americans (disambiguation) In arts and entert ...
to the
Great Lakes region The Great Lakes region of North America is a binational Canadian–American region that includes portions of the eight U.S. states of Illinois, Indiana, Michigan, Minnesota, New York, Ohio, Pennsylvania and Wisconsin along with the Canadian p ...
of eastern North America. It has lavender blue or violet-blue flowers, a very short stem and long fan-like green leaves. It is cultivated as an ornamental plant in
temperate In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout ...
regions. It is closely related to '' Iris cristata'' (another North American crested iris).


Description

It is similar in form to ''Iris cristata'' but is chromosomally different and smaller.British Iris Society (1997) James Cullen, Sabina G. Knees, H. Suzanne Cubey (Editors) It has slender, wiry,Richard Lynch or cord-like, greenish-brown, or yellow rhizomes. It has a large central section and outer sections, which are long and 0.8–1.2 cm wide. The outer sections have fibrous roots (underneath), and 2–3 brown scale-like leaves above. It creeps across the ground, creating thick clumps of plants.William Cullina It has 8–12 sheathing, (fan-like), green or light green, basal leaves. They are falcate (
sickle A sickle, bagging hook, reaping-hook or grasshook is a single-handed agricultural tool designed with variously curved blades and typically used for harvesting, or reaping, grain crops or cutting Succulent plant, succulent forage chiefly for feed ...
-shaped) or sword-shaped, and linear,Merel R. Black and Emmet J. Judziewicz and long and 10–8 mm wide. After flowering, the leaves elongate up to long and 10 mm wide. When the plant is not in flower, the leaves of the iris might be confused with false asphodel, ('' Triantha glutinosa'', a white flowered member of the
lily ''Lilium'' () is a genus of herbaceous flowering plants growing from bulbs, all with large prominent flowers. They are the true lilies. Lilies are a group of flowering plants which are important in culture and literature in much of the world. M ...
family whose leaves are much narrower) which lives in similar habitats. Although, the flower stem of false asphodel is much longer than that of iris and very sticky. It has very short stems, which are long. The stems and flowers are shorter than the leaves. It has green
spathe In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves. They may be smaller, larger, or of ...
s (leaves of the flower bud), which are slightly keeled, and long. They have scarious (membranous) edges. The short stems have 1 to 2 flowers, in Spring, or summer (in Europe), in April, or May, or early June, or July. In Spring, it can flower up to 7 to 10 days earlier than ''Iris cristata'', and it can have later flush of flowers in the fall (or Autumn), or October. The flowers are in diameter, come in shades of blue, violet-blue, sky blue, deep blue, lavender blue, lilac, or deep purple. A white form has occasionally, also been found. It has 2 pairs of petals, 3 large sepals (outer petals), known as the 'falls' and 3 inner, smaller petals (or
tepals A tepal is one of the outer parts of a flower (collectively the perianth). The term is used when these parts cannot easily be classified as either sepals or petals. This may be because the parts of the perianth are undifferentiated (i.e. of very ...
), known as the 'standards'. The obovate shaped, falls are long and 0.8 cm wide. They taper towards the claw (section closest to the stem). They have a white signal patch, which has a deep violet margin, and 3 central, orange, gold, or yellow and white toothed (or fimbriated – fringed) ridges (or crests). The signal patch guides bumblebees in to the middle of the flower, to
pollinate Pollination is the transfer of pollen from an anther of a plant to the stigma of a plant, later enabling fertilisation and the production of seeds, most often by an animal or by wind. Pollinating agents can be animals such as insects, birds, a ...
it. The standards are narrowly oblanceolate, long and 0.4–0.5 cm wide. They are shorter and narrower than the falls. It has a yellow funnel-like, perianth tube, which is 1–2 cm long. The tube is shorter than ''Iris cristata''. It has a trigonal (or triangular), ovary, which is 0.8–1 cm long. It has a 1–2 cm long style, which has linear crests and wavy (crenate) edges. The style arm guides bumblebees to the lower section of the sepal, to reach the nectar. After the iris has flowered, between late June to late July, it produces a roundly triangular, or ovoid, seed capsule, which is covered by the spathes. The capsules are 1.2 mm long and 8 mm wide. Inside the capsule, are 3 mm wide, dark brown seeds, which have a white appendage (or aril, fleshy thickening of seed coat), spiralled around the seed. This spiral or corkscrew-like appendage is called an ''eliaosome''. The eliaosomes are used as energy-rich food sources by ants, who help pollinate the plant.


Biochemistry

In 1994, a study was carried out on the genetic make-up of ''Iris lacustris''. In 2000, a study was carried out on ''Iris cristata'' and ''Iris lacustris'', looking at the genetic variation of both irises. As most irises are diploid, having two sets of
chromosomes A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are ...
, this can be used to identify hybrids and classification of groupings. It has been counted several times, 2n=42, Simonet, 1934; n=21, 2n=42, Chimphamba, 1973 and 2n=32, Pringle, 1976. It is normally published as 2n = 32, 42.


Taxonomy

The Latin name is pronounced ''Iris'' (EYE-ris) ''lacustris'' (lak-US-triss). It has the common name of dwarf lake iris, lake iris, and Great Lakes iris. The Latin specific epithet ''lacustris'' means "of lakes". The iris was found on Mackinac Island in 1810 by
Thomas Nuttall Thomas Nuttall (5 January 1786 – 10 September 1859) was an English botanist and zoologist who lived and worked in America from 1808 until 1841. Nuttall was born in the village of Long Preston, near Settle in the West Riding of Yorkshire and ...
. The botanist travelled from
Detroit Detroit ( , ; , ) is the largest city in the U.S. state of Michigan. It is also the largest U.S. city on the United States–Canada border, and the seat of government of Wayne County. The City of Detroit had a population of 639,111 at t ...
by canoe with French Canadian voyagers and the surveyor for the Michigan Territory. It was first then published and described by Thomas Nuttall, in 'The Genera of North American Plants' (published in Philadelphia, USA) Volume 1, Issue 23 on 14 July 1818. An illustration of the iris was published in ''Wild flowers of the United States'' by Rickett, plate 11 in 1966. It was verified by
United States Department of Agriculture The United States Department of Agriculture (USDA) is the federal executive department responsible for developing and executing federal laws related to farming, forestry, rural economic development, and food. It aims to meet the needs of com ...
and the Agricultural Research Service on 15 April 1994, then updated on 3 December 2004. It is a close relative to ''Iris cristata'', the only other crested iris native to North America. However, unlike it, ''Iris lacustris'' is found only in small areas of the Great Lakes region that have been
glacier A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such as ...
-free for only 11,000 years. It was once thought to be a form of ''Iris cristata'', (by
William Rickatson Dykes William Rickatson Dykes (4 November 1877 – 1 December 1925) was an English amateur botanist who became an expert in the field of iris breeding and wrote several influential books on the subject. He was also interested in tulips, amaryllis, ...
in 1913 and other authors), later chromosomal studies confirmed the two were separate species.


Distribution and habitat

''Iris lacustris'' is
native Native may refer to: People * Jus soli, citizenship by right of birth * Indigenous peoples, peoples with a set of specific rights based on their historical ties to a particular territory ** Native Americans (disambiguation) In arts and entert ...
to temperate regions of northern America.


Range

It is found in
Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...
, within the province of
Ontario Ontario ( ; ) is one of the thirteen provinces and territories of Canada.Ontario is located in the geographic eastern half of Canada, but it has historically and politically been considered to be part of Central Canada. Located in Central C ...
(on the
Bruce Peninsula The Bruce Peninsula is a peninsula in Ontario, Canada, that divides Georgian Bay of Lake Huron from the lake's main basin. The peninsula extends roughly northwestwards from the rest of Southwestern Ontario, pointing towards Manitoulin Island, ...
and
Manitoulin Island Manitoulin Island is an island in Lake Huron, located within the borders of the Canadian province of Ontario, in the bioregion known as Laurentia. With an area of , it is the largest lake island in the world, large enough that it has over 100 ...
). It is found in U.S.A., within the states of
Michigan Michigan () is a U.S. state, state in the Great Lakes region, Great Lakes region of the Upper Midwest, upper Midwestern United States. With a population of nearly 10.12 million and an area of nearly , Michigan is the List of U.S. states and ...
,
Wisconsin Wisconsin () is a state in the upper Midwestern United States. Wisconsin is the 25th-largest state by total area and the 20th-most populous. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake M ...
, and, infrequently in
Ohio Ohio () is a state in the Midwestern region of the United States. Of the fifty U.S. states, it is the 34th-largest by area, and with a population of nearly 11.8 million, is the seventh-most populous and tenth-most densely populated. The sta ...
.Tom S. Cooperrider, Allison Cusick, John T. Kartesz (Editors) It is found on northern shores and smaller islands of Lake Michigan, Lake Huron, and
Lake Superior Lake Superior in central North America is the largest freshwater lake in the world by surface areaThe Caspian Sea is the largest lake, but is saline, not freshwater. and the third-largest by volume, holding 10% of the world's surface fresh wa ...
, within the Great Lakes region. The majority of iris populations are within 500 m of the shore of Lake Huron, but the largest ones can occur up several kilometres away from the lake.


Habitat

It grows on the Great Lakes shorelines in cool, moist lake shore air. It is found on sand, or in thin soil over limestone-rich gravel, in
calcareous Calcareous () is an adjective meaning "mostly or partly composed of calcium carbonate", in other words, containing lime or being chalky. The term is used in a wide variety of scientific disciplines. In zoology ''Calcareous'' is used as an ad ...
(chalky) soil, or bedrock. It also grows on
alvar An alvar is a biological environment based on a limestone plain with thin or no soil and, as a result, sparse grassland vegetation. Often flooded in the spring, and affected by drought in midsummer, alvars support a distinctive group of prair ...
limestone barrens, and along shorelines, old beach ridges, beside streams, in ditches, on cliffs, behind open dunes, or at the edges of coniferous woods (in Canada and Michigan).


Conservation

''Iris lacustris'' is designated a "vulnerable"
threatened species Threatened species are any species (including animals, plants and fungi) which are vulnerable to endangerment in the near future. Species that are threatened are sometimes characterised by the population dynamics measure of '' critical depen ...
by federal, state and provincial laws throughout its distribution
range Range may refer to: Geography * Range (geographic), a chain of hills or mountains; a somewhat linear, complex mountainous or hilly area (cordillera, sierra) ** Mountain range, a group of mountains bordered by lowlands * Range, a term used to i ...
. It was added to the U.S. List of Endangered and Threatened Wildlife and Plants on September 28, 1988. It is on the
U.S. Fish and Wildlife Service The United States Fish and Wildlife Service (USFWS or FWS) is an agency within the United States Department of the Interior dedicated to the management of fish, wildlife, and natural habitats. The mission of the agency is "working with othe ...
's endangered species program. It was listed by the federal U.S. government as 'threatened' since February 1, 2001. It has become threatened due to habitat destruction, from shoreline development, from road-widening projects, chemical spraying and salting, and off-road vehicle use have caused disturbance and destruction of habitat, and degradation of habitats. Due to being a protected species, plants can not be dug up or seeds gathered. A permit is required for any project (including research, development, and construction) which may "take" or "harm" threatened or endangered species in Michigan. Also 37% of the Canadian population is on land in protected areas. Shoreline development has also improved some habitats by opening up the canopy and creating new open ground.


Cultivation

It is hardy to between
USDA The United States Department of Agriculture (USDA) is the federal executive department responsible for developing and executing federal laws related to farming, forestry, rural economic development, and food. It aims to meet the needs of com ...
Zone 4 and Zone 7. and European Zone H2 It is hardy in Europe, and in the UK. It is tolerant of a range of soils, but prefers moist, slightly acidic neutral soils. It flowers mostly in semi-open habitats with partial sun. Although it can tolerate sunny sites. It can grow in a peat bank, or can be grown in a six-inch pot or similar container. It is rarely offered for sale in Europe. A specimen has been grown in
Cambridge Botanic Garden The Cambridge University Botanic Garden is a botanical garden located in Cambridge, England, associated with the university Department of Plant Sciences (formerly Botany School). It lies between Trumpington Road to the west, Bateman Street to ...
.


Toxicity

Like many other irises, most parts of the plant are poisonous (rhizome and leaves), if mistakenly ingested can cause stomach pains and vomiting. Handling the plant may also cause a skin irritation or an allergic reaction.


Culture

In 1998, ''Iris lacustris'' was designated the state wildflower of Michigan, where the vast majority of populations exist.


References


Other sources

* Center for Plant Conservation. Center for Plant Conservation National Collection of Endangered Plants (on-line resource). * FNA Editorial Committee. 1993–. Flora of North America. * Gleason, H. A. & A. Cronquist. 1991. Manual of vascular plants of north eastern United States and adjacent Canada, ed. 2. * Kartesz, J. T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. * Mathew, B. 1981. The Iris. 74–75. * Scoggan, H. J. 1978–1979. The flora of Canada, 4 vol. * United States Fish and Wildlife Service. U.S. Fish & Wildlife Service. Species Information: threatened and endangered animals and plants (on-line resource). * Voss, E. 1972–. Michigan flora.


External links


USDA PLANTS profile: ''Iris lacustris'' (dwarf lake iris)
{{Taxonbar, from=Q6070364 lacustris Flora of the Great Lakes region (North America) Flora of Michigan Flora of Ontario Flora of Wisconsin Flora of Canada Flora of Ohio Vulnerable plants Symbols of Michigan Plants described in 1818