The pollination biology of North American orchids brings together, for the first time, a comprehensive treatment of this information for all native and introduced North American orchids found north of Mexico and Florida. It provides detailed information on genetic compatibility, breeding systems, pollinators, pollination mechanisms, fruiting success, and limiting factors for each species. Distribution, habitat, and floral morphology are also summarized. In addition, detailed line drawings emphasize orchid reproductive organs and their adaptation to known pollinators.This, the first of two volumes, furnishes a brief introduction to the general morphology of the orchid flower and the terminology used to describe orchid breeding systems and reproductive strategies. It treats the lady’s-slippers of genus cypripedium, subfamily cypripedioideae, and nine genera of the subfamily orchidoideae, including the diverse rein orchids of genus platanthera.