Cypripedium arietinum

Life-forms

Classification System: APG IV

Superregnum: Eukaryota
Regnum: Plantae
Cladus: Angiosperms
Cladus: Monocots
Ordo: Asparagales

Familia: Orchidaceae
Subfamilia: Cypripedioideae
Genus: Cypripedium
Subgenus: Cypripedium subg. Cypripedium
Sectio: Cypripedium sect. Arietinum
Species: Cypripedium arietinum
Name

Cypripedium arietinum R.Br. in W.T.Aiton, Hortus Kew. 5: 222. (1813)
Synonymy

Homotypic
Criosanthes arietina (R.Br.) House, Bull. Torrey Bot. Club 32: 374 (1905)
Heterotypic
Criosanthes borealis Raf., Amer. Monthly Mag. & Crit. Rev. 2: 268 (1818)
Arietinum americanum L.C.Beck, Bot. North. Middle States: 352 (1833)
Cypripedium arietinum f. albiflorum House, Bull. New York State Mus. Nat. Hist. 243-244: 48 (1923)
Cypripedium arietinum f. biflorum P.M.Br., N. Amer. Native Orchid J. 1: 198 (1995)

Distribution
Native distribution areas:

Northern America
Western Canada
Manitoba, Saskatchewan.
Eastern Canada
Nova Scotia, Ontario, Québec.
North-Central U.S.A.
Minnesota, Wisconsin.
Northeastern U.S.A.
Connecticut, Maine, Massachusetts, Michigan, New Hampshire, New York, Vermont.

References: Brummitt, R.K. 2001. TDWG – World Geographical Scheme for Recording Plant Distributions, 2nd Edition
References
Primary references

Brown, R. 1813. Hortus Kewensis; or, a Catalogue of the Plants Cultivated in the Royal Botanic Garden at Kew. London (2nd ed.) 5: 222.

Additional references

Cribb, P. 1997. The Genus Cypripedium. Portland, Oregon: Timber Press ("Botanical Magazine Monographs"); Royal Botanical Gardens, Kew. ISBN 0-88192-403-2
Eccarius, W. 2009. Die Orchideengattung Cypripedium. Phylogenie, Taxonomie, Morphologie, Biologie, Verbreitung, Ökologie, Hybridisation. Bürgel, Germany: EchinoMedia Verlag Dr. Kerstin Ramm, 384 pp. ISBN 978-3-937107-19-6 Reference page.
Pridgeon, A.M., Cribb, P.J., Chase, M.W. & Rasmussen, F.N. (eds.) 1999. Genera Orchidacearum Volume 1: General Introduction, Apostasioideae, Cypripedioideae; page 114 ff., Oxford: Oxford University Press. ISBN 0-198505-13-2

Links

Global Biodiversity Information Facility. 2022. GBIF Backbone Taxonomy. Checklist dataset. Taxon: Cypripedium arietinum. Accessed: 2022 Jan 30.
Govaerts, R. et al. 2022. Cypripedium arietinum in Kew Science Plants of the World online. The Board of Trustees of the Royal Botanic Gardens, Kew. Published online. Accessed: 2022 Jan 30. Reference page.
Govaerts, R. et al. 2022. Cypripedium arietinum in Kew Science Plants of the World online. The Board of Trustees of the Royal Botanic Gardens, Kew. Published online. Accessed: 2022 Jan 30. Reference page.
Hassler, M. 2022. Cypripedium arietinum. World Plants: Synonymic Checklists of the Vascular Plants of the World In: Roskovh, Y., Abucay, L., Orrell, T., Nicolson, D., Bailly, N., Kirk, P., Bourgoin, T., DeWalt, R.E., Decock, W., De Wever, A., Nieukerken, E. van, Zarucchi, J. & Penev, L., eds. 2022. Species 2000 & ITIS Catalogue of Life. Published online. Accessed: 2022 Jan 30. Reference page.
International Plant Names Index. 2022. Cypripedium arietinum. Published online. Accessed: 30 Jan 2022.
Tropicos.org 2022. Cypripedium arietinum. Missouri Botanical Garden. Published online. Accessed: 30 Jan 2022.

Vernacular names

Deutsch: Widder-Frauenschuh
English: Ram's head lady's slipper
français: Cypripède tête-de-bélier
русский: Башмачок раноголовый

Cypripedium arietinum, the ram's head lady's slipper,[1] is a rare orchid that grows in lightly shaded areas with calcareous soils. It is characteristic of the alvars around the Great Lakes in North America, as well as in New England.[1][2] In Canada, it is found from Quebec to Saskatchewan, plus an isolated population in Nova Scotia, where it grows on gypsum based soils, 330 km away from the nearest population in Maine.[3][4]

Description

Cypripedium arietinum is a herbaceous perennial small lady's slipper growing to 10–40 cm (4–16 in). It typically has 3, but sometimes 4-5, leaves and normally has a single flower per flowering stem but in the form biflorum there maybe two flowers per stem.[5] 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.[6] The other sepal is broadly elliptic to ovate-lanceolate in shape. It flowers in May and June. The diploid (2n) chromosome count is 20.[5]
Distribution and habitat

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), or Picea mariana (black spruce) where it grows on small mounds produced by Sphagnum mosses.[6] It more commonly occurs in upland forests dominated by coniferous tree species such as Pinus resinosa (red pine) or Pinus banksiana (jack pine) in weakly acidic (or nearly neutral) soils composed of either loam or clay, it is also found in sandy soils.[6]
Conservation

Cypripedium arietinum is considered rare to extremely rare in all locations where it occurs.[3] More specifically, it is rare in Ontario[7] and rare in Manitoba. The ram's head lady's slipper is a threatened plant species in other areas within its range, including Wisconsin, Minnesota, Michigan, and Saskatchewan. It is believed to be extirpated in Connecticut. This species is listed as an endangered species in Nova Scotia.[8]

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.
References

USDA, NRCS (n.d.). "Cypripedium arietinum". The PLANTS Database (plants.usda.gov). Greensboro, North Carolina: National Plant Data Team. Retrieved 1 July 2016.
Catling, P.M.; Brownell, V.R. (1999). "Alvars of the Great Lakes Region". In Anderson, R. C.; Fralish, J. S.; Baskin, J. M. (eds.). Savannas, Barrens and Rock Outcrop Communities of North America. Cambridge: Cambridge University Press. pp. 375–391. ISBN 9780511574627.
Blaney, S.; Mazerolle, D. (2007). Nova Scotia Provincial Status Report on Ram's-Head Lady Slipper (Cypripredium arietinum R. Br.). Nova Scotia Department of Natural Resources.
"Cypripedium arietinum". County-level distribution map from the North American Plant Atlas (NAPA). Biota of North America Program (BONAP). 2014.
"Cypripedium arietinum in Flora of North America @ efloras.org". www.efloras.org. Retrieved 2020-12-11.
Barbara Coffin; Lee Pfannmuller (1988). Minnesota's Endangered Flora and Fauna. U of Minnesota Press. p. 84. ISBN 978-0-8166-1689-3.
Oldham, M.J.; Brinker, S.R. (2009). Rare Vascular Plants of Ontario (4th ed.). Peterborough, Ontario: Natural Heritage Information Centre, Ontario Ministry of Natural Resources.
"Species at Risk Overview". Nova Scotia Department of Natural Resources. Retrieved 15 July 2018.