Indigenous peoples traditionally used this plant for medicinal purposes. For example, Algonquin people, who form part of the larger cultural group known as the Anishinaabeg,[6] traditionally used C.acaule to treat menstrual disorders.[7] Due to population decline, harvesting for medicinal purposes is no longer recommended. As C.acaule takes many years to go from seed to mature plant, the gathering of seed-bearing specimens is presently unsustainable.[8]
Name
Cypripedium acaule is commonly referred to in English as the pink lady's slipper or moccasin flower.[9][10][11] The specific epithetacaule means "lacking an obvious stem",[12] a reference to its short underground stem, for which reason the plant is also known as the stemless lady's-slipper.[13] In Anishinaabemowin, it is known as makizinkewe.[14]
Description
Cypripedium acaule is a perennial plant.[15][16] The plant has a solitary flower, which means only one flower blooms on its peduncle between the two large basal leaves per season.[17] It grows slowly and up to 0.4m (1ft 4in).[18] Unlike most other species of Cypripedium, the pouch of C.acaule opens in a slit that runs down the front of the labellum rather than a round opening. The plant consists of two plicate leaves near the ground. From between those leaves sprouts a long, pubescent stalk that bears a single pink flower. The sepals and petals tend to be yellowish-brown to maroon with a large pouch that is usually some shade of pink but can be white to nearly magenta. Leaves are simple, elliptical in shape and opposite in arrangement.[19]
Plant in bloom near Mount Stewart, Prince Edward Island, Canada
The genus Cypripedium is one of five genera in the subfamily of slipper orchids Cypripedioideae. Cypripedium acaule was first described in the Western European tradition by the Scottish botanist William Aiton in 1789. He referred to it as the two-leaved lady's slipper.[20]
They get pollinated by attracting bees into the slit of the pink flower, but the bees eventually stop visiting them as it provides them with no benefits.[19][21] Therefore, they are also called non-rewarding flowers because they offer no food or even produce any nectar but still get pollinated. [22]The two main frequent pollinators observed visiting C. acaule are B. vagans and B. borealis queens, therefore it is believed that queen bees are their primary pollinators. [23][17]
C.acaule, like many other orchids rely on pollinator deception, which means they attract insects via colour, shape and scent cues instead of providing nectar.[24] The labellum in Cypripedium acuale acts like a one way trap, once a bee enters, it crawls past the pollen structure before exiting. In this process they pollinate the flower by first picking up pollen from the male counterpart and depositing it to the female counterpart.[22]
Once pollinated, the ovary of the flower turns into a oblong shaped green seed pod with pointy ends. The seed pod supposedly stays green until the temperature drops and them splits open releasing tiny powdery seeds that resembles white pepper. [25]
Distribution and habitat
Cypripedium acaule can be found in the eastern third of the United States, particularly in the Great Lakes region and the Northeast in New Hampshire and Maine, south along the Appalachians to Alabama. It is widespread in Canada, where it is found in every province except British Columbia. It also occurs in the Northwest Territories and in St. Pierre & Miquelon.[26][27] Within its geographic range, it can be found in a wide variety of environments, from coastal plains, to pine barrens, to mountaintops.
C. acaule requires highly acidic soil and tolerates a range of shade and moisture, though it prefers at least partial shade and well-drained slopes[17]. It is usually found in pine forests with sandy soils[28], where it can be seen in large colonies, but it also grows in deciduous woods. Since they are highly sensitive to shade and soil disturbances, they are classified as forest habitat species, which means that they are typically associated with shaded, mature forest conditions and any kinds of changes to its environment can has a potential negative impact on their population.[29] It was long speculated that a fungal association was needed for growth,[30][31] and that C.acaule could not be artificially cultivated outside of these associations[32]. However, a greater understanding of orchids in general has shown that this association is only needed to germinate orchid seeds and is not required once plants begin making true leaves. Some disturbances that affects C. acaule's survival and population include canopy removal, forest floor and soil disturbance, all of which likely reduce the habitat suitability (shade, moisture, mycorrhizal associations).[29]
Seed germination labs have increased the commercial availability of C.acaule, although it still tends to be less commonly available than other Cypripedium species and hybrids. This is primarily due to the extra care that must be provided if the growing site is not naturally suitable for in-ground cultivation. This plant grows in soils below a pH of 5, often at 4–4.5. At this high acidity soil fungus is suppressed, and C.acaule can thrive. There is even evidence that it is partially myco-heterotrophic, parasitizing fungus that attempts to invade its roots. However, in soils above pH 5, soil microbes become more than C.acaule can manage, and the plants rot. Seedlings germinated in a sterile environment can grow and thrive in a much higher pH than 5, but must be grown below 5 if removed from the sterility.
For artificial cultivation, container culture is a must, and the growing medium must be naturally acidic. Additionally, all other soil additives must be devoid of any calcium that could buffer the pH to above 5. High quality peat moss or pine duff work well, and pH neutral perlite can be added to improve porosity. Due to the risk of calcium bicarbonate, tap water is unsuitable. Rainwater or distilled water mixed with 2 ounces (57g) of vinegar per gallon will assure that a reliably high acidity is maintained in the growing medium. Give bright dappled shade or morning sun. Sink pots in winter or store in a cold frame for insulation. Given these conditions, C.acaule can thrive indefinitely, but it will always require much more maintenance than other species/hybrids that can be grown in a wider pH range.
↑Voitk, Andrus; Voitk, Maria (2006). Orchids on the Rock: The Orchids of Newfoundland. Rocky Harbour, NL: Gros Morne Co-operating Association.
↑Cribb, Phillip; Green, Peter (1997). The Genus Cypripedium. Kew Royal Botanic Gardens and Timber Press. ISBN0-88192-403-2.
↑Dickinson, T.; Metsger, D.; Bull, J.; Dickinson, R. (2004). ROM Field Guide to Wildflowers of Ontario. Toronto: Royal Ontario Museum and McClelland and Stewart Ltd. p.89.
↑Aiton, William (1789). "Cypripedium acaule". Hortus Kewensis; or, a Catalogue of the Plants Cultivated in the Royal Botanic Garden at Kew. 3. London: 303. Retrieved 6 March 2021.
↑Kartesz, John T. (2014). "Cypripediumacaule". County-level distribution map from the North American Plant Atlas (NAPA). Biota of North America Program (BONAP).
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