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Black-spored Quillwort

Isoetes melanospora




Black spored quillwort
 Isoetes melanospora colony
 Isoetes melanospora



Black spored quillwort habitat
 Isoetes melanospora solution pool
 Outcrop habitat



Status under the U.S. Endangered Species Act

Federal Endangered (February 5, 1988)

State Heritage Status Rankings

Georgia (S1), South Carolina (S1)



 
Description:

Black-spored quillwort is a perennial fern ally that forms small tufts of erect to spreading, linear leaves, 2.5 to 8 cm in height from a spirally arranged bulbous rootstock. The species produces dark-colored spores (most other quillworts have whitish spores) from early May to June (NatureServe 2003). This plant's distinguishing characteristics include complete velum coverage, dark tuberculate megaspores and short (2 to 7 cm or O.8 to 2.8 inches long) spiraled leaves. Immature plants may have distichous leaves. Black-spored quillwort often hybridizes with Piedmont quillwort (Isoetes piedmontana) in habitats which are ecologically intermediate between the two species. A more common granite outcrop quillwort, Piedmont quillwort, has incomplete velum coverage, white megaspores, and longer leaves (7 to 15 cm or 2.8 to 5.9 inches long) (USFWS 1991).

Habitat:

Black-spored quillwort is endemic to shallow, flat-bottomed, rock rimmed solution pools that are formed in depressions on granitic outcrops (Patrick et. al. 1995). These depressions are less than 3 dm in depth and usually contain at least 2 cm of soil (NatureServe 2003).

Range:

Black-spored quillwort is historically known from 14 sites in Georgia and 1 site in South Carolina. Due to destruction of its habitat the species now only survives at only 9 locations in the world. Black-spored quillwort is endemic to granite outcrop communities, found in rock-rimmed solution pools. Rock outcrop communities in the southeastern United States are rapidly being destroyed by dumping of garbage by local citizens, rock quarrying, and heavy recreational use such as hiking and off road vehicle use (NatureServe 2003).





References

  • NatureServe. 2003. Internet resource. NatureServe.

  • Patrick, T.S., Allison, J.R., and Krakow, G.A. 1995. Protected Plants of Georgia: AN INFORMATION MANUAL ON PLANTS DESIGNATED BY THE STATE OF GEORGIA AS ENDANGERED, THREATENED, RARE, OR UNUSUAL. Georgia Natural Heritage Program. Internet Resource. Protected Plants of Georgia.

  • USFWS. 1991. 3 GRANITE OUTCROP PLANTS: Black-Spored Quillwort (Isoetes melanospora), Mat-Forming Quillwort (Isoetes tegetiformans), and Little Amphianthus (Amphianthus pusillis). Internet Resource Three Granite Outcrop Plants (Accessed December 8, 2003).

  • USDA, NRCS. 2002. The PLANTS Database, Version 3.5. Internet Resource USDA Plants Database. National Plant Data Center, Baton Rouge, LA 70874-4490 USA.