Regularity: Regularly occurring
Comments: Margins of post oak (Quercus stellata) woodlands in sandy loams along intermittent tributaries of rivers. Often in areas where edaphic or hydrologic factors (such as high levels of aluminum in the soil or a perched water table) limit competing vegetation in the herbaceous layer. Besides post oak, associated species include water oak (Q. nigra), blackjack oak (Q. marilandica), and yaupon (Ilex vomitoria).
Life History and Behavior
National NatureServe Conservation Status
Rounded National Status Rank: N3 - Vulnerable
NatureServe Conservation Status
Rounded Global Status Rank: G3 - Vulnerable
Reasons: Primarily known from 2 river drainages in east-central Texas, with 1 location in east Texas. Although about 100 populations with a total of about 10,000 plants are currently known, many of the sites are threatened by strip mining. Rapid urban expansion has also encroached on some of the species' habitat.
Date Listed: 05/06/1982
Lead Region: Southwest Region (Region 2)
Listing status: E
For most current information and documents related to the conservation status and management of Spiranthes parksii, see its USFWS Species Profile
Comments: Commercial develpment, lignite mining, cattle grazing, road building and maintenance.
Spiranthes parksii (Navasota Ladies'-tresses) is a species of orchid that is endemic to Texas, United States. The flower was first discovered in 1945 and was first described by Donovan Stewart Correll in his 1950 book, Native Orchids of North America North of Mexico.
Spiranthes parksii is a slender-stemmed perennial, 8–15 inches (200–380 mm) tall. Leaves are long and thin and found mostly near the ground level, but usually disappear when the flower buds. Flowers petals are round or oval and off-white in color. The flowers typically spiral up the stem. Conspicuously white-tipped bracts occur underneath each 1⁄4-inch-long (6.4 mm) flower. The side petals have a green central stripe, and the lip (bottom petal) is distinctly ragged.
Habitat and range
Navasota ladies-tresses is primarily found in the East Central Texas forests, usually along creeks in the Brazos and Navasota River watersheds. In 1982, when the species was listed as endangered, only two populations were believed to exist, both in Brazos County. Since then, biologists have identified the species in Bastrop, Burleson, Fayette, Freestone, Grimes, Jasper, Leon, Madison, Milam, Robertson, and Washington Counties. The population in Jasper County is disjunct and the only one that occurs in the Piney Woods.
Navasota ladies'-tresses was listed as an endangered species by the United States Fish and Wildlife Service (USFWS) in May 1982. The decline of the plant is mostly due to loss of habitat from human encroachment and activity.
- "Spiranthes parksii - Correll Navasota Ladies'-tresses". NatureServe Explorer. NatureServe. Retrieved 2013-02-08.
- "Taxon: Spiranthes parksii Correll". Germplasm Resources Information Network. United States Department of Agriculture. 2000-03-23. Retrieved 2013-02-08.
- "Navasota Ladies'-tresses (Spiranthes parksii)". Texas Parks and Wildlife. Retrieved 2013-02-08.
- Pelchat, Cliff (March 2005). "Spiranthes parksii Correll - Navasota Ladies' Tresses". The McAllen International Orchid Society Journal 6 (2): 9–15.
Names and Taxonomy
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