Prairies and marshes; also gravelly calcareous shores. In Eastern Ontario their exclusive habitat is the wettest parts of calcareous sedge fens, which may preclude ankle deep water, or at least damp peat in dry years.

Height to 60 cm., mostly less than 40 cm. Stem leafy, angled.
Leaves 1 - 5, typically 2 - 4, clasping the stem, upper leaves smaller.
Raceme large, showy, 15 - 40 flowers.
Flower, creamy-white with a three-lobed, fringed lip and a long curving spur; fragrant at sunset. Pollinated by moths, including the large sphinx moth.

Originally a plant of the wet prairies of the Mississippi Valley, habitat now largely destroyed by farming. One of our largest and most fragrant orchids, now restricted to open fen habitat where it is easily seen during its blooming period. Individual flowers are each about the size of a quarter.

Orchids of Ontario
The Canadian Field-Naturalist
The Orchids of Bruce & Grey