Featured in Wildflowers of the World – Apr 8, 2011
Featured in Endangered or Vulnerable Plants – June 4, 2010

Cypripedium acaule (Orchidaceae) – this native orchid, also known as Pink Lady’s-Slipper prefers acid soil such as is found in pine woods. They bloom in late spring.

The Lady’s Slipper is known in the United States and Canada as the Moccasin Flower, from its resemblance to a shoe or moccasin.

The Pink Lady’s Slipper is a herbaceous perennial with thick fibrous roots. It has two large, basal leaves; that is, the leaves seem to grow from the base of the plant, next to the ground. The leaves, up to 20 cm long, are strongly veined, elliptic in shape, and are thinly pubescent (have a thin covering of short hairs). They are a medium green in color and may have lighter colored spots. A single flower stalk arises from between the two leaves growing to as much as 40 cm above the ground. Each stalk produces a solitary flower. The large (3 – 6 cm long), inflated lip of the flower (the slipper part) is usually dark pink in color, but the shade will vary, and white varieties are known. The sepals and petals surrounding the lip are usually reddish brown, but may be tinged with green. The sideways pointing petals are twisted into a spiral.

Loss of native orchid species and their habitat is a significant environmental problem in Manitoba as it is all over the world. Habitat loss is the primary threat to native orchid species. Most of our orchid species grow in or adjacent to wetlands and Manitoba has lost 70% of its wetlands since 1900. Another critical orchid habitat, for our three endangered species, is the Tall Grass Prairie. We have less than 1% of our Tall Grass Prairie remaining. Agriculture and housing development, resource extraction such as logging and mining, and wetland drainage are all major causes of habitat loss. Failure to thrive, including an inability to reproduce sexually due to pollinator loss, disease and environmental stress, are all related to habitat loss and/or modification.

Photographed in St. Rita, Manitoba, Canada on a very rainy day