Cypripedium reginae

Habitat

Cypripedium reginae grows in wetlands such as fens and open wooded swamps that are sometimes populated by tamarack and black spruce.[7] Cyp. reginae thrives in neutral to basic soils but can be found in slightly acidic conditions. The plants often form in clumps by branching of the underground rhizomes. Its roots are typically within a few inches of the top of the soil. It prefers very loose soils and when growing in fens it will most often be found in mossy hummocks.

Showy Lady's Slipper in its natural habitat.

This photo, taken in a forested, calcareous fen in Williamstown, MA, is only one of 14 occurrences currently documented in the state (1984 to the present 2016).^[8] The increasing rarity of this plant is attributable to destruction of a suitable alkaline habitat – and an exploding deer population whose browsing stunts or eliminates its growth. It can tolerate full sun but prefers partial shade for some part of the day. When exposed to full sun, the flower lip is somewhat bleached and less deeply colored. It is occasionally eaten by white-tailed deer.[8] Cypripedium reginae can be found in Canada from Saskatchewan east to Atlantic Canada, and the eastern United States south to Arkansas and Tennessee.^[2]

Conservation

Flower in profile

C. reginae at the Minnesota Landscape Arboretum

Cypripedium reginae is quite rare, and is considered imperiled (SRANK S2) or critically imperiled (S1) in Arkansas, Connecticut, Illinois, Iowa, Missouri, New Brunswick, New Hampshire, New Jersey, Newfoundland and Labrador, North Dakota, Nova Scotia, Ohio, Pennsylvania, Prince Edward Island, Saskatchewan, Tennessee, Virginia and West Virginia. Additionally, it is considered vulnerable (S3) in Indiana, Maine, Manitoba, Massachusetts, New York, Quebec, Vermont, Minnesota, Wisconsin, Rhode Island, and several areas of east Canada.^[9]

It was historically found in Kentucky and North Carolina, but has not been found recently. The only province to rank C. reginae as apparently secure (S4) is Ontario.

The Showy Lady's-Slipper is sensitive to hydrologic disturbances, and is threatened by wetland draining, habitat destruction and horticultural collectors.

Cultivation

The Showy Lady's Slipper is a popular plant among orchid collectors for its color and structure. However, it has proven to be a difficult plant to cultivate, due to its poor seed germination and slow maturation to flowering. This makes it more vulnerable to illegal collection. It was difficult to raise from seed, taking many months to germinate in sterile culture until progress on axenic culture from seed in the 1990s by a group of high school students in New Hampshire.^{[10][3][11][12]} Efforts at micropropagation have had marginal success.^[4][13]

Reproduction

Cyp. reginae reproduces sexually and depends on insects such as syphid flies, beetles and Megachile bees for pollination. The structure of the flower creates a tight space through which insects have to squeeze. A pollinating insect first passes by the stigma, and upon exiting the trap rubs against the anther. Pollination typically occurs in June and the seed pod or fruit is ripe by September and dehisces by October.^[14] Although a single seed pod can produce over 50,000 seeds, low germination and a seed-to-flowering term of about 8 years indicate that sexual reproduction is inefficient. Asexual reproduction from rhizomes in the Showy Lady's slipper is a common means of sustaining a population.

It flowers in early to midsummer, usually with 1 to 2 flowers per stalk, less commonly 3 or 4.

Medicine

The Cypripedium species have been used in native remedies for dermatitis, tooth aches, anxiety, headaches, as an antispasmodic, stimulant and sedative. However, the preferred species for use are Cypripedium parviflorum and Cypripedium acaule, used as topical applications or tea.^[16][17]