''Cypripedium arietinum'', the ram's head lady's slipper, is a rare terrestrial

orchid Orchids are plants that belong to the family Orchidaceae (), a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant. Orchids are cosmopolitan plants that are found in almost every habitat on Eart ...

that grows in lightly to heavily shaded areas with

calcareous Calcareous () is an adjective meaning "mostly or partly composed of calcium carbonate", in other words, containing lime (mineral), lime or being chalky. The term is used in a wide variety of Science, scientific disciplines. In zoology ''Calcare ...

soils. It is characteristic of the

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 prairie ...

s around the

Great Lakes The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes spanning the Canada–United States border. The five lakes are Lake Superior, Superior, Lake Michigan, Michigan, Lake Huron, H ...

in North America]. In Canada, it is found from

Quebec Quebec is Canada's List of Canadian provinces and territories by area, largest province by area. Located in Central Canada, the province shares borders with the provinces of Ontario to the west, Newfoundland and Labrador to the northeast, ...

Saskatchewan Saskatchewan is a Provinces and territories of Canada, province in Western Canada. It is bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, to the northeast by Nunavut, and to the south by the ...

, plus an isolated population in

Nova Scotia Nova Scotia is a Provinces and territories of Canada, province of Canada, located on its east coast. It is one of the three Maritime Canada, Maritime provinces and Population of Canada by province and territory, most populous province in Atlan ...

, where it grows on gypsum based soils, 330 km away from the nearest population in Maine.

Description

''Cypripedium arietinum'' is a herbaceous perennial small lady's slipper growing to . It typically has 3, but sometimes 4-5, leaves and normally has a single flower per flowering stem but in the form biflorum there may be two flowers per stem. The purplish-red flower has light venation and is white at the lip. The flower has three petals, one modified into a densely hairy pouch with white and purplish markings. The sepals are green with reddish-brown markings and the side sepals are to some degree spirally twisted, linear to linear-lanceolate in shape, and are free, in contrast to other North American species in this genus. The other sepal is broadly elliptic to ovate-lanceolate in shape. It flowers in May and June. The diploid (2n) chromosome count is 20.

Distribution and habitat

While populations of Cypripedium arietinum are declining elsewhere in eastern North America, the orchid flourishes abundantly in Anticosti Island, making the island a refuge for this plant. ''Cypripedium arietinum'' is a forest understory species, it occurs in coniferous to mixed forests and in bogs dominated by ''Thuja occidentalis'' ( northern white cedar), ''Larix laricina'' (

tamarack ''Larix laricina'', commonly known as the tamarack, hackmatack, eastern larch, black larch, red larch, or American larch, is a species of larch native to Canada, from eastern Yukon and Inuvik, Northwest Territories east to Newfoundland, and als ...

), or ''Picea mariana'' (

black spruce ''Picea mariana'', the black spruce, is a North American species of spruce tree in the pine family. It is widespread across Canada, found in all 10 provinces and all 3 territories. It is the official tree of Newfoundland and Labrador and is tha ...

) where it grows on small mounds produced by ''

Sphagnum ''Sphagnum'' is a genus of approximately 380 accepted species of mosses, commonly known as sphagnum moss, also bog moss and quacker moss (although that term is also sometimes used for peat). Accumulations of ''Sphagnum'' can store water, since ...

'' mosses. In Minnesota, it more commonly occurs in upland forests dominated by coniferous tree species such as ''Pinus resinosa'' (

red pine ''Pinus resinosa'', known as red pine (also Norway pine in Minnesota), is a pine native to Eastern North America. Description Red pine is a coniferous evergreen tree characterized by tall, straight growth. It usually ranges from in heigh ...

) or ''Pinus banksiana'' (

jack pine Jack pine (''Pinus banksiana''), also known as grey pine or scrub pine, is a North American pine. Distribution and habitat Its native range in Canada is east of the Rocky Mountains from the Mackenzie River in the Northwest Territories t ...

) in weakly acidic (or nearly neutral) soils composed of either loam or clay, it is also found in sandy soils. In northern New England, it often is found in mixed hardwood and softwood forests.

Conservation

''Cypripedium arietinum'' is considered rare to extremely rare in all locations where it occurs. More specifically, it is rare in

Ontario Ontario is the southernmost Provinces and territories of Canada, province of Canada. Located in Central Canada, Ontario is the Population of Canada by province and territory, country's most populous province. As of the 2021 Canadian census, it ...

and rare in

Manitoba Manitoba is a Provinces and territories of Canada, province of Canada at the Centre of Canada, longitudinal centre of the country. It is Canada's Population of Canada by province and territory, fifth-most populous province, with a population ...

. The ram's head lady's slipper is a threatened plant species in other areas within its range, including

Wisconsin Wisconsin ( ) is a U.S. state, state in the Great Lakes region, Great Lakes region of the Upper Midwest of the United States. It borders Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake Michigan to the east, Michig ...

Minnesota Minnesota ( ) is a U.S. state, state in the Upper Midwestern region of the United States. It is bordered by the Canadian provinces of Manitoba and Ontario to the north and east and by the U.S. states of Wisconsin to the east, Iowa to the so ...

Michigan Michigan ( ) is a peninsular U.S. state, state in the Great Lakes region, Great Lakes region of the Upper Midwest, Upper Midwestern United States. It shares water and land boundaries with Minnesota to the northwest, Wisconsin to the west, ...

, and

. It is believed to be

extirpated Local extinction, also extirpation, is the termination of a species (or other taxon) in a chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinctions. Local extinctions mark a chan ...

Connecticut Connecticut ( ) is a U.S. state, state in the New England region of the Northeastern United States. It borders Rhode Island to the east, Massachusetts to the north, New York (state), New York to the west, and Long Island Sound to the south. ...

. This species is listed as an endangered species in

. The ram's head lady's slipper is difficult to cultivate and rarely survives transplantation to a garden from the wild. It should never be removed from any natural area. Conservation efforts of ''Cypripedium arietinum'' in New England have been advancing with the optimization of asymbiotic sterile seed germination and sterile seedling cultures. This research is being presented and published in the 2024 World Orchid Conference in Taiwan and in the Orchid Digest. Lan Grace, Palifka Nicholas, Sun Ian, Sun Kevin, Anderson Kastner. (2024). Conservation of the Cypripediums of New England. Orchid Digest, Vol. 88-2, Apr., May, June. (in print)

References

External links

* * {{Taxonbar, from=Q1306340 arietinum Orchids of Canada Orchids of the United States Flora of Maine Flora of Manitoba Flora of Michigan Flora of Minnesota Flora of Nova Scotia Flora of Ontario Flora of Saskatchewan Flora of Wisconsin Taxa named by Robert Brown (botanist, born 1773)