Northern Prairie Wildlife Research Center
Federally Listed Endangered, Threatened, and Candidate Species 1995
Western Prairie Fringed Orchid (Platanthera praeclara)
- Official Status: Threatened
- Threatened species are species that are likely to become endangered species within the foreseeable future throughout all or a significant portion of their range.
- 54 Federal Register 39863; September 28, 1989
- Historical Status:
- The Western prairie fringed orchid was historically found throughout the tall grass regions of North America. This included the Dakotas, Nebraska, Kansas, Oklahoma, Missouri, Iowa, Minnesota and Manitoba. The Mississippi River was the eastern limit of its range.
- Present Status:
- According to county records, the Western prairie fringed orchid has experienced at least a 60 percent decline from historic times. Presently, there are at least 37 separate populations remaining in 7 states. It appears to be extirpated from South Dakota. In North Dakota there is a large scattered population in the Sheyenne National Grasslands in the southeastern part of the state. This population numbers over 2,000 individuals.
- The Western prairie fringed orchid occurs in moist tall grass prairies and sedge meadows. In North Dakota, it is commonly found with sedges, reedgrass, and rushes or where those plants meet big bluestem, little bluestem, and switchgrass. The Western prairie fringed orchid is well adapted to survive fires. It does not appear that light grazing negatively affects the Western prairie fringed orchid although researchers are still studying the relationship.
- Life History:
- The vegetative shoots of the Western prairie fringed orchid emerge in late May. Flowers do not emerge until mid June to late luly. The entire plant can display flowers for about 21 days with individual flowers lasting up to 10 days. Flowers must be pollinated for seed production. Pollination of the Western prairie fringed orchid appears to be accomplished only by hawkmoths. The microscopic seeds are dispersed by the wind in early fall. The Western prairie fringed orchid is a perennial, which means that an individual plant may live for many years.
- Aid to identification:
- The Western prairie fringed orchid is distinguished by large, white flowers that come from a single stem. Up to 20 flowers may occur on a single plant. The flower is fringed on the margins, giving it a feathery appearance. The Western prairie fringed orchid grows up to 3 feet high. The 2 to 5 leaves are narrow and hug the stem.
- Reasons for decline:
- The main reason for the decline is that historic prairie habitat has been converted to cropland. Herbicides and the introduced plant, leafy spurge, may also have a negative affect on the Western prairie fringed orchid. Heavy grazing and early haying can be detrimental.
- Notify a natural resources agency of any suspected Western prairie fringed orchids. This includes populations that were visible in the past but have not recently been observed.
- The Eastern prairie fringed orchid is similar to the Western prairie fringed orchid, however, it inhabits primarily areas east of the Mississippi River. The Eastern prairie fringed orchid is also listed as a threatened plant.
- A recovery plan for the Western prairie fringed orchid is in preparation (U.S. Fish and Wildlife Service). Western Prairie Fringed Orchid by Minnesota Department of Natural Resources, 1991.
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