Counties where the Western prairie fringed orchid can be found are in black.
Western Prairie Fringed Orchid Platanthera praeclara
Status: Threatened
Description: The Western prairie fringed orchid is a single-stemmed plant with up to
25 white showy flowers. It may grow to nearly four feet tall, but is
generally shorter. The white flowers have lower petals which are deeply
three-lobed and fringed. Flowers may be up to one and one-half inches in
the Western prairie fringed orchid.
Habitat and Habits: The Western prairie fringed orchid occurs in
moist to wet native prairie areas. These include prairie remnants along
roads and railroad rights-of-way. This orchid blooms from early June to
late July in Iowa. A species of sphinx moth or hawk moth is the
pollinator for the orchid. At dusk, the flower releases a scent which
attracts the insect. The moth sips nectar from the flower and in the
process, pollen may be deposited on the moth. The moth flies to another
flower to gather more nectar and pollinates that flower with pollen from
previously visited flowers. On small prairie remnants or in small
populations of this orchid, pollination appears to be rare. There may
not be enough flowering orchids to attract pollinators, or the prairie
may be too small to harbor a good population of the appropriate insects.
Thus, in some years few or no seeds are produced. In the short term,
this may not be a problem as the orchid is a long-lived perennial.
However, in the long term, the orchid population must reproduce by seed
in order to insure genetic diversity and to colonize new sites.
Vegetative reproduction (reproducing without seed) does occur, but is
probably infrequent and insufficient to maintain a population over a
long period of time.
Distribution: The Western prairie fringed orchid is restricted to
the Midwest, the Great Plains and one Canadian province. In Iowa, it
currently occurs on 33 sites in 18 counties. Thirteen of the populations
are on land managed by conservation agencies -- eight owned by the Iowa
Department of Natural Resources, two by The Nature Conservancy/Iowa
Chapter, and three by county conservation boards.
Conservation Efforts: Populations should be protected on private
lands by working with landowners and testing management techniques such
as the time and frequency of prescribed burns on public lands.
Reasons For Listing: The conversion of prairie for agriculture,
roads and other developments has left less than one percent of the
original prairie in Iowa. This loss of suitable habitat is the reason
for the major population decline of the Western prairie fringed orchid
in Iowa.
Funding Provided
by U.S. Environmental Protection Agency and
