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Description:
Pool sprite is a small, annual aquatic herbaceous plant with a fibrous root system inhabiting rock rimmed solution pools in outcrop communities. The species exhibits both leaves on the water's surface as well as below the surface. Floating leaves (those above the water's surface) are in pairs and ovate. Each leaf is approximately 4 to 8 mm in length by 3 to 5 mm in width attached to the plant via very thing petiols. The summerged leaves are found on top of a short stem approximatetly 6 mm or less in length and are lanceolate in shape and less than 1 cm in length. Pool sprite produces tiny, inconspicuous white to pale violet flowers in March and April, which may be present on both the tops of the floating leaves as well as on those below the water's surface. Fruit is produced from April to May and are a shallowly bilobed capsule approximately 1 to 2 mm in length by 2 to 3 mm in width (Patrick et. al. 1995 and USFWS 1991). Ideal moisture and light conditions are required for successful seed germination and growth. The dormancy period for the seeds is unknown. An entire life cycle for Amphianthus usually lasts only 3 to 4 weeks (USFWS 1991).
Habitat:
Pool sprite is endemic to shallow, rock-rimmed, flat-bottomed solution pools (vernal pools) on granitic outcrop communities. The solution pools are less than 1 foot in depth exhibiting a soil substrate less than 2 cm in depth. See above images. The pool sprite in the right image was found in a solution pit in which the water had recently evaporated (Patrick et. al. 1995). The number of individuals in the pools range from a dozen to several thousand. When rainfall is sufficient, most pools contain several hundred plants (USFWS 1991).
Range:
Pool sprite is endimic to granite outcrops of the southeastern Piedmont (mostly in Georgia). Comprehensive surveys have been conducted throughout this species' range and, as of 1994, only 57 extant populations were known. Locally, the plants may occur in high densities (NatureServe 2003). The most severe threat to pool sprite is the destruction of its habitat by rock quarrying. Rock mining companies own 17.4% of the outcrops surveyed for pool sprite populations in Georgia. The dumping of garbage on out crop communities by private citizens and companies as well as driving vehicles across them essentially destroys the required habitat for outcrop plant species. Serious disturbance can result from vehicular traffic such as driving trucks and ATVs through the pools, pets or people playing in the pools or as previously mentioned, dumping garbage or even rocks into the pools (NatureServe 2003). These activities not only crush and potentially kill outcrop plant species, but they also loosen the soil. Overuse of the outcrop communities for recreation can be a threat, especially if campfires are built in the dry solution pools (Patrick et. al. 1995). As can be seen in Georgia as well as other states, juveniles and adults sometimes spray-painted gang signs and other graphite on outcrop communities (Author's personal observation of outcrop community in Georgia containing Federally protected plants). The introduction of toxic paints into the solution pools may also kill outcrop species, many of which are federally protected such as pool sprite and quillwort (Isoetes) species (NatureServe 2003). The USFWS (1991) states that pool sprite was first discovered in Alabama and is historically known from 5O sites in Georgia. As of 1991, pool sprite occurred at 39 sites in 17 Georgia counties, three sites in two Alabama counties, and three sites in three South Carolina counties. Twelve of the 17 Georgia counties (Rockdale, Walton, Douglas, Butts, Putnam, Oglethorpe, Harris, Meriwether, Henry, Pike, Newton, and Gwinnett) support a limited population (1 to 5 pools) with eight of these county records confined to only a single site. One or two extensive populations (15 to 25 pools) are located in Dekalb, Heard, Greene, Hancock, and Columbia counties, Georgia. Limited populations of three pools exist in Randolph and Chambers counties in Alabama. Two sites contain fewer than 5O plants in a single vernal pool, while the third population consists of several hundred plants in two to three pools. In South Carolina, half of the 12 existing pools had extensive populations of more than 2OO plants, and six had limited populations of less than 25 plants during the 1983 and 1984 growing seasons. Seven pools exist in Lancaster County, one in Saluda, and four in York County (USFWS 1991).
References
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