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Biosurvey News The Newsletter of the Oklahoma Biological Survey Spring 2013 Biodiversity: The Federally Endangered Harperella Oklahoma’s first and only federally listed endangered vascular plant recently was discovered in southeastern Oklahoma. An endangered species is one that is in danger of extinction throughout all or a significant portion of its range. Oklahoma does have two plants (the prairie white fringed orchid and the Great Plains white fringed orchid) listed as threatened, or likely to become endangered, but these are considered extirpated from the state. Harperella (Harperella nodosa; Apiaceae) was listed by the U.S. Fish and Wildlife Service in 1988. Only 45 occurrences in 24 watersheds are known, with the largest concentration of populations found along the Maryland/West Virginia border and in Arkansas. Around 25 percent of known occurrences have not been seen in 20 years. Harperella is an aquatic, primarily annual herb. The inflorescence is an umbel of small white flowers quite similar to other members of the carrot family. The most distinguishing character of the plant is its unusual leaf form. Leaves are reduced to a hollow, septate central stalk, or "rachis leaf"—an adaptation to a semi-aquatic habitat. Harperella blooms from May through October. Population sizes may vary dramatically from year to year in response to water levels. The Oklahoma population was found along a river in the southeastern part of the state and included two stands of approximately 500 plants. Harperella populations face many threats. The plant is vulnerable to fluctuating water levels from dredging, dam and reservoir construction and wetland draining. It can be affected by reductions in water quality from pollution, algae and erosion and siltation from logging and road construction. Invasive plants also may be an issue. Specific threats to the Oklahoma population include increased siltation from timber harvesting, run-off from ranching and poultry farming, the possibility of out-of-state water transfers and recreational activity. The region has experienced drought conditions since 2010 as well, and these could eventually affect river flow. (Continued on page 2) Harperella in flower. Photo by Amy Buthod. Harperella habitat. Photo by Amy Buthod.
|Okla State Agency||
Biological Survey, Oklahoma
|Okla Agency Code||
|Title||Biosurvey news, spring 2013|
Oklahoma Biological Survey.
|Purpose||Biodiversity: the federally endangered Harperella; OBS Welcomes New Faculty Member [Dr. Lara Souza]; Something's Fishy in the Tree of Life; OBS Welcomes New Faculty Member: Eli Bridge; BioBlitz! 2012 at Foss Reservoir; Oklahoma's BioBlitz! Origins: Ian Butler; Status of the Lesser Prairie Chicken, Michael Patten|
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|Digital Format||PDF, Adobe Reader required|
|ODL electronic copy||Downloaded from agency website: http://www.biosurvey.ou.edu/download/newsletter/Spring2013BiosurveyNews.pdf|
|Rights and Permissions||This Oklahoma state government publication is provided for educational purposes under U.S. copyright law. Other usage requires permission of copyright holders.|