The pink lady's slipper (Cypripedium acaule) is a terrestrial or ground-rooted orchid, one of many types of terrestrial orchids native to the United States. They are closely related to the showy paphiopedilum tropical orchids often displayed at orchid shows. These pink-flowered, woodland plants generally flower in the late spring or early summer, depending on location. Because of development and other factors, lady's slippers are considered endangered in many places.
The name "pink lady's slipper" is the key to the plant's most notable feature, a rosy-pink, slipper-shaped "pouch" that is the most prominent part of the flower. The plant also features two long, broad leaves at ground level. Each plant produces only a single stalk, usually about 5 inches tall, which in turn supports only a single flower. Lady's slippers often appear in groups or colonies.
History and Lore
Cypripedium acaule is also known as "moccasin flower," for the shape of its pink pouch, and "nerveroot," because its roots were once used medicinally as a calming agent. Because of the relative rarity of the plants, herbalists now prefer other botanical remedies for nervousness. Its close relative, the pink and white lady's slipper (Cypripedium reginae), is the state flower of Minnesota.
The plants are found in clearings and at the edges of woodlands in northeastern to north central Canada and the United States.
Pink lady's slippers are notoriously difficult to cultivate. Success in growing varieties from seeds requires not only rich, acidic soil, but also the presence of a specific microrrhizal fungus in the soil. Transplanting specimens is difficult because the roots tend to be brittle. The combination of brittle roots and the absence of the fungus means that even if transplants thrive at first, they will eventually die. Some nurserymen have succeeded in propagating lady's slippers through tissue culture, making plants more readily available to the public.
If you want to buy pink lady's slippers from a nursery or catalog, make sure that the plants have not been collected from the wild. Nursery labels can be confusing in this respect. There is a difference between plants labeled "nursery grown" and those marked "nursery propagated." Nursery grown plants may have been collected from the wild when young and grown on at the nursery. Nursery propagated plants are started at the nursery, either from seed or by vegetative propagation. Insisting on nursery propagated plants saves wild populations.