Last week Leonard and I were delighted to find a mountain lady’s slipper (Cypripedium montanum) along the PSEA Trail at Burney Falls State Park CA. This beautiful member of the Orchid Family is a rare and endangered species with numbers continuing to decline. It can be found growing in the duff of conifer forests or on slopes in mixed conifer-deciduous forests in northwestern United States and Canada.
Mountain lady’s slippers are perennials arising from underground rhizomes. They can remain in a vegetative state for 12 to 15 years before flowering. The glandular stem is simple or branched. The stem glands exude a substance that can cause a rash similar to poison oak/ivy. There are 4 to 7 oval leaves alternately arranged on the stem. The conspicuously veined leaves clasp the stem. One to three flowers can arise from the leaf axils. Bilaterally symmetrica,l the flowers have three sepals and three petals. The flower parts are dark brown or copperish except for a single, white petal that is inflated into a showy pouch. The pouch or slipper has purple veins. The remaining sepals and petals are long and twisted. The stamens are fused to the style and the ovary is inferior. The mountain lady’s slipper fruit is an oblong capsule that contains thousands of microscopic seeds which are carried by the wind.
Also called a moccasin flower, mountain lady’s slipper must have an association with a specific fungus to survive. Because the wind-borne seeds are small, they do not have large food reserves. This is where the fungus plays a role. The fungus “attacks” the lady’s slipper seeds, whereupon the seeds “feed” on the fungus, deriving the energy necessary for germination and seedling establishment. This fungal association can continue throughout the life of the plant. Unfortunately, mountain lady’s slipper plants are often collected from the wild and transplanted in gardens that do not have the appropriate fungus. Thus these beautiful plants die.
In addition to collection for horticultural and ornamental uses, mountain lady’s slippers are collected for medicinal use by pregnant women. Habitat loss, a decrease in pollinator (small native bees) abundance and habitat disturbance by logging and for recreational uses also are responsible for decreasing mountain lady’s slipper numbers. This is one plant that should only be “collected” by camera.
The common names, slipper and moccasin, refer to the shape of the lower inflated petal. The genus name, Cypripedum, means “Aphrodite’s foot” and derives from “Kypris”, which was the old Greek name for Aphrodite (Venus).
Leonard and I feel fortunate to have discovered this rare orchid.