Trichomanes boschianum

Trichomanes boschianum, the Appalachian bristle fern or Applachian filmy fern, is a small delicate perennial leptosporangiate fern which forms colonies with long, black creeping rhizomes. The evergreen fronds are bipinnatifid, deeply and irregularly dissected, about 4 to 20 cm long, 1 to 4 cm across with winged stipes 1 to 7 cm long and light green in colour. The common name derives from the leaves which are very thin, only a single cell thick, missing an epidermis and translucent, giving the appearance of a wet film.