As a component of the All Taxa Biodiversity Inventory in the Great Smoky Mountain National Park, a re-evaluation of the pteridophyte flora is being undertaken. In addition to the inventory of species, we are also mapping the distribution of ferns in the park. Currently there are 64 species of pteridophytes reported from the GSMP. Twenty-five (39%) are considered to be rare in the park. There are historical records for Lycopodium annotinum, Thelypteris simulata, and T. phaegopteris. It has been determined that T. simulata, had incorrect label data and was not collected inside the park. Searches for specimens of the other historical records have been made and are thought to be extripated from this area. A tetraploid species of Isoetes, was recently collected in the Cade's Cove area, and is currently under investigation by both Dr. Carl Taylor and Kerry Heafner. A few of the other rare species known from the GSMNP are Asplenium pinnatifidum, Botrychium lanceolatum var. anustisegmentum, B. matricarifolium, Lygodium palmatum, and Woodwardia virginica.

Key words: distributional data, ferns, flora, inventory, Pteridophyte, rare plants