Prairie Fringed Orchid (Platanthera leucophaea)
Synonyms: Habenaria leucophaea (Nutt.) Gray
Description: Herbaceous perennial; 0.2-1.2 m.; lanceolate leaves several to many, scattered along stem; flowers white or creamy, deeply 3-lobed, margins fringed, column appears hooded; flowers arranged in a cylindric spike.
Flowering: June - August; Fruiting: August - October
Similar Species: Vaguely similar to Platanthera blephariglottis and P. lacera var. lacera. P. leucophaea has the lip in three divisions and has cream-white flowers; P. blephariglottis has no divisions to the lip and has white flowers. The flowers of P. lacera var. lacera are greenish and are smaller than the flowers of P. leucophaea. Occasional albino forms of P. psycodes and P. grandiflora may resemble P. leucophaea. P. leucophaea has a slightly longer spur and deeper fringing of the lip than these two species; however, careful examination and measurements of the flowers are necessary for positive identifications.
Total Range: USA: IA, IL, IN, ME, MI, MO, NY, OH, OK, PA, VA, WI; CAN: ON.
Ohio Range: Auglaize, Clark, Erie, Holmes, Lucas, Montgomery, Ottawa, Sandusky, and Wayne counties. Braun (1967) maps Champaign and Franklin counties.
Habitats: Full sun; neutral to calcareous soils; mesic to wet prairies, marshes, fens, and old fields.
Threats: P. leucophaea grows well in areas that are good agricultural sites. Drainage and utilization for cropland has destroyed most of the original populations. It is also threatened by succession to woody species and invasion of exotic species. Invasive species such as reed canary grass (Phalaris arundinacea), glossy buckthorn (Frangula alnus), purple loosestrife (Lythrum salicaria) and common reed grass (Phragmites australis ssp. australis) are species commonly overtaking orchid habitat. In addition, over collection is always a threat to this rare and conspicuous plant. Conservation Potential: The persistence of this species in Ohio is dependent upon habitat protection and management. Some populations are known to occur in areas that were at one time heavily disturbed. These disturbed communities can contain large orchid populations, but without management, have a low long-term viability. Sheviak (1974) believes that prairie fires may stimulate this species to flower.
Inventory Guidelines: Mature flowering material is needed for identification. Avoid over-collecting.
Comments: Like many other temperate terrestrial orchids, P. leucophaea may exhibit dramatic changes in population numbers from year to year. This plant was collected in 1980 in two separate sites after an apparent 64-year lag in collections. In 1982, it was found in an area that was a cornfield in 1972. New sites may be discovered in prairie and fen areas in Ohio.
This species has very specific needs for reproduction including a particular pollinator (hawkmoth) and reliance on mycorrhizal fungi (Bowles et al. 2002). It is highly susceptible to inbreeding and vegetative spread is very rare.
Argus, G.W. and D.J. White. 1982. Atlas of the rare vascular plants of Ontario: Part 1. National Museums of Canada, Ottawa, Canada. Ayensu, E.S. 1975. Endangered and threatened orchids of the United States. Am. Orchid Soc. Bull. 44: 384-394.
Bowles, M. L. and K.A. Jacobs. 2002. Crossing effects on seed viability and experimental germination of the federal threatened Platanthera leucophaea (Orchidacea). Rhodora, Vol. 104, No. 917.
Bowles, M.L. 1983. The tallgrass prairie orchids Platanthera leucophaea (Nutt.) Lindl. and Cypripedium candidum Muhl. ex Willd.: some aspects of their status, biology, and ecology, and implications toward management. Nat. Areas J. 3(4): 14-37.
Braun, E.L. 1967. The Monocotyledoneae of Ohio: Cat-tails to orchids. The Ohio State University Press, Columbus, OH. 464 pp.
Case, F.W., Jr. 1964. Orchids of the western Great Lakes region. Cranbrook Institute of Science Bull. No. 48, Bloomfield Hills, MI. 147 pp.
Crow, G.E. 1982. New England's rare, threatened, and endangered plants. U.S. Government Printing Office, Washington, DC. 130 pp.
Cuthrell, D.L. et al. 1999. The pollinators of Ohio and Michigan populations of Eastern prairie fringed orchid (Platanthera leucophaea). Report submitted to the U.S. Fish and Wildlife Service.
Flora of North America Editorial Committee. 2002. Flora of North America North of Mexico,Vol. 26, Magnoliophyta: Liliidae: Liliales and Orchidales. Oxford University Press. New York, New York. 723 pp.
Luer, C.A. 1975. The native orchids of the United States and Canada excluding Florida. New York Botanical Garden, New York, NY. 361 pp.
Mitchell, R.S. and C.J. Sheviak. 1981. Rare plants of New York State. New York State Museum Bull. 445. 96 pp.
Sheviak, C.J. 1974. An introduction to the ecology of the Illinois Orchidaceae. Illinois State Museum, Springfield, IL. 90 pp.
Spooner, D.M. 1981. Status reports for 20 native Ohio plant taxa considered for listing as Federal endangered or threatened. Ohio Department of Natural Resources, Division of Natural Areas and Preserves, Columbus, OH.
Spooner, D.M., A.W. Cusick, B. Andreas, and D. Anderson. 1983. Notes on Ohio vascular plants previously considered for listing as Federally endangered or threatened. Castanea 48: 250-258.
U.S. Fish and Wildlife Service. 1999. Eastern prairie fringed orchid (Platanthera leucophaea) recovery plan. Fort Snelling, Minnesota. 62 pp. Wallace, L. 1999. Conservation genetics and pollination ecology of the Eastern prairie white fringed orchid (Platanthera leucophaea) in Ohio. Progress report to the Ohio Department of Natural Resources Division of Natural Areas and Preserves, Columbus, Ohio.
Windus, J.L. and K.E. Cochrane. 1997. Monitoring of Eastern prairie white-fringed orchid (Platanthera leucophaea) in Ohio: 1992-1996, A summary of data to date. Report submitted to the U.S. Fish and Wildlife Service.
For more information contact:
Division of Natural Areas and Preserves