|Listed||January 21, 1987|
|Description||Annual herb with low-growing stems, scalelike leaves, and numerous tiny white flowers.|
|Habitat||Sand pine scrub.|
|Threats||Agricultural and residential development, fire suppression, off-road vehicles.|
Papery whitlow-wort, Paronychia chartacea, is an annual herb, growing up to 4 in (10 cm) tall, that forms bright green mats of many stems radiating from a taproot. Stems fork repeatedly, bearing leaves that are scalelike and rarely longer than 0.12 in (3 mm). Numerous white flowers appear alone or in clusters of three. The flowers, which bloom in summer, have five tiny sepals and lack petals. The whitlow-wort is easily distinguished from other members of its genus by its mat-forming habit, scalelike leaves, and tiny flowers. This species has also been referred to as Nyachia pulvinata.
Papery whitlow-wort occurs in bare, sandy clearings within sand pine scrub vegetation, and is nearly always found with inopina oak and rosemary. The papery whitlow-wort is often found in association with railroad and highway right-of-ways, along fence lines, and bordering cattle pastures. The populations that are in association with pastures grow in the transition zone from pasture to undisturbed scrublands.
Sand pine scrub is a transitional habitat that is renewed by periodic brushfires or by brush removal. After 20 or 30 years, herbs such as whitlow-wort, are forced out by other vegetation. Herbs, such as rosemary, are characteristic of early successional development in scrub and are often absent from later stages.
Florida sand pine scrub supports dozens of endemic plants that have become increasingly rare, including the federally endangered wireweed (Polygonella basiramia ).
Papery whitlow-wort was found historically in the inland scrub region of south-central Florida. At the end of the twentieth century, small populations of papery whitlow-wort were located in Lake, Orange, Polk, and Highlands Counties in Florida. Protected whitlow-wort sites in the southern Lake Wales Ridge included Arbuckle Lake Wildlife Management Area and Archbold Biological Station. The plant was also present in the Saddle Blanket Lakes tract in southern Polk County, and a portion of that tract had been purchased by the Nature Conservancy. The plant was also thought to be present in Highlands Hammock and Arbuckle Lake State Parks.
Much of the whitlow-wort's native habitat has been converted into citrus groves. During the late twentieth century, residential development claimed large tracts of scrub. Stands of scrub in some areas had become fragmented and survived as "waste areas"—vacant lots, roadsides, and railroad rights-of-way. This plant was also vulnerable to off-road vehicles, which disturb the stability of the sandy soils.
Conservation and Recovery
Recovery of this species requires the reclamation and active management of large tracts of scrub vegetation. Regular controlled burns are needed to maintain the habitat. To these ends, the Florida Natural Areas Inventory has acquired several parcels of sand pine scrub in Highlands and Polk Counties. The state of Florida funds land acquisition through taxes on the phosphate mining industry and other land users. Acquisition of these parcels provides some security for whitlow-wort and lessens the danger to other rare endemic plants.
"The Recovery Plan for Nineteen Florida Scrub and High Pineland Plants," first announced in draft form by the U. S. Fish and Wildlife Service in 1995, outlines elements necessary to restore the papery whitlow-wort and other endangered plants of the area, including habitat protection through land purchase and other means (including the Habitat Conservation Plan process for threatened animals in the Florida scrub habitat); the management of protected habitats; the assessment of progress; and postrecovery monitoring.
This plan is a revision and expansion of a recovery plan, published in 1990, that covered 11 of these plant species. The 1990 edition emphasized the need for land acquisition to protect these plants. At the time, the state and private organizations had already made significant acquisitions, and more have been accomplished since then (including the initial land purchase for the Lake Wales Ridge National Wildlife Refuge). These land purchases, accompanied by the other elements of the recovery plan, are likely to assure the full recovery or at least the downlisting or even delisting of the large majority of the 19 plants, including the papery whitlow-wort.
U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
1875 Century Blvd., Suite 200
Atlanta, Georgia 30345
Abrahamson, W. G. 1984. "Post-Fire Recovery of the Florida Lake Wales Ridge Vegetation." American Journal of Botany 71: 9-21.
Wunderlin, R. P. 1982. Guide to the Vascular Flora of Central Florida. University Presses of Florida, Gainesville.
Wunderlin, R. P., D. Richardson, and B. Hansen.1981. "Status Report on Paronychia chartacea. " U. S. Fish and Wildlife Service, Atlanta.