A family of about 10 genera and 100 species.
Vittaria Smith (Shoestring Fern)
References: Farrar in FNA (1993b); Farrar & Mickel (1991). Key adapted from Farrar in FNA.
A genus of about 50 species, tropics and subtropics.
1. Sporophytes present, the leaves linear, 10-60 cm long and 1-3 mm wide......[V. lineata]1. Gametophytes only present......2
2. Gemmae with 4-16 body cells; end cells of gemmae equal to or smaler than the medial cells; rhizoid primordia regularly present on the end cells, as well as on some medial cells; sporophytes frequently produced (and small sporophytes often present in largely gametophytic colonies)......[V. lineata]
Vittaria appalachiana Farrar & Mickel, Appalachian Shoestring Fern, "Appalachian Gametophyte." Mt (NC, SC, VA), Pd (NC, VA): shaded grottoes, undersides of overhanging rock outcrops, especially in moist gorges or on spray cliffs in the vicinity of waterfalls, usually on felsic metamorphic rocks, such as mica schist, mica gneiss, granite gneiss, or metaquartzite; rare (NC Watch List, VA Watch List). This reduced species consists of "a branched, ribbon-like thallus one cell in thickness, usually differentiated into basal and upright branches; basal branches attached to the substrate by numerous short, brown rhizoids emanating from marginal and interior cells; upright branches terminating in the production of gemmae" (Farrar & Mickel 1991). The species is often overlooked or mistaken for a liverwort; it is most often collected by bryologists and hepaticologists, and was first noted in 1824 by von Schweinitz, who considered it a Jungermannia. Its range is in the Southern and Central Appalachians, south of the glacial boundary, from se. PA, sw. NY, and ne. OH south through c. TN and c. KY to n. GA and n. AL. Although this species has been known for some time (often referred to as the "Appalachian Gametophyte"), it was only recently named formally (Farrar & Mickel 1991). A range of evidence (morphologic, electrophoretic, and developmental) indicates that it is not the gametophyte of any known Vittaria sporophyte; instead, it is a distinct taxon, reproducing vegetatively by gemmae, having lost the capability of producing sporophytes. For additional information, see Farrar (1974), Farrar (1978), Gastony (1977), Farrar, Parks, & McAlpin (1983), and Pittillo et al. (1975). [= FNA; "a branching, ribbon-like gametophyte, with diffuse rhizoids and linear-shaped gemmae only one cell wide, of the genus Vittaria" -- RAB; "thalloid, irregularly shaped gametophytes of a species of Vittaria" -- C]
Vittaria lineata (Linnaeus) Smith, Shoestring Fern, ranges north to se. GA, and formerly to ec. GA. It is normally found as an epiphyte on the bark of Sabal palmetto, but the northernmost site (in Lincoln County, GA, adjacent to SC) was on rock. Sporophytic plants have pendant linear leaves, 1-3 mm wide and up to 60 cm long.
Flora of the Carolinas and Virginia, Working Draft of 27 October 1997 -- KEY TO PTERIDOPHYTE GENERA. Alan S. Weakley. The Nature Conservancy, Southeast Regional Office, Southern Conservation Science Department.