An ecological study of Cypripedium passerinum Rich. (Sparrow's Egg Lady-shpper, Orchidaceae) on the north shore of Lake Superior

An ecological study of Cypripedium passerinum was conducted on the north shore of Lake Superior near the mouth of the Pic River. Here C. passerinum occurs in sand dune complexes in a wide variety of habitats ranging from open grass-covered dunes to stabilized dunes with Picea glauca forest. C. passerinum begins to flower in mid-June and immature capsules can be found in early July. Flower mortality was caused by insect damage (1%) and an unknown agent (12%). High capsule set in undamaged flowers (99%) suggested autogamy was occurring. Seed dispersal is not synchronized in any manner. c. passerinum may take approximately 15 years to flower from seed. Four species from three insect orders (Hymenoptera, Diptera, Lepidoptera) fed on C. passerinum . Within-group recruiitment was largely the result of vegetative reproduction alone. The habitat occupied by C. passerinum is a changing environmental mosaic, and this has important implications for species management.