References: Smith in FNA (1993b); Lellinger (1985); Mickel (1979).
A family of 6-30 genera (generic circumscription especially controversial and problematic) and about 900 species.
1. Leaf blades 7-25 (-30) cm long, triangular, not more than 2H as long as wide; rachis with adnate wings between the pinnae; sori without indusia; midribs of pinnae lacking an adaxial groove...... Phegopteris 1. Leaf blades (15-) 20-100 cm long, lanceolate, oblong-lanceolate, or triangular, more than 2H as long as wide; rachis without adnate wings between the pinnae; sori with reniform indusia; midribs of pinnae with an adaxial groove (adaxial groove lacking in Macrothelypteris)...... 2
A genus of about 10 species, tropical and subtropical.
*Macrothelypteris torresiana (Gaudichaud-BeauprJ) Ching, Mariana Maiden Fern. Cp (SC): disturbed areas; rare, introduced from the Asian and African tropics. Leonard (1972) discusses the history of this species in the southeastern United States. [= FNA, K; Dryopteris setigera Blume -- S, misapplied; Thelypteris torresiana (Gaudichaud-BeauprJ) Alston]
A genus of 3 species, north temperate and boreal.1. Rachis wings absent between the two basal pinna pairs; rachis bearing on its lower surface numerous tan to brown, lanceolate scales (these mostly 6-12 cells wide at the base) and acicular hairs 0.3-1.0 mm long...... Ph. connectilis
1. Rachis wings present between the two basal pinna pairs; rachis bearing on its lower surface relatively few, white to pale tan, narrowly lanceolate scales (these mostly 3-5 cells wide at thebase) and hairs 0.1-0.25 mm long...... Ph. hexagonoptera
Phegopteris connectilis (Michaux) Watt, Northern Beech Fern. Mt (NC): moist cliffs where wet by spray from waterfalls (at medium elevations), also on high elevation cliffs wet by seepage and in spruce-fir forests; rare (NC Candidate). April-August. A circumboreal species, at its southern limit in North America in NC, TN, IA, MT, and OR. Most of the occurrences in NC are at waterfalls in the escarpment gorges of Transylvania, Macon, and Jackson counties, near Highlands. The Southern Appalachian occurrences are disjunct; the species ranges south to WV, and is apparently absent from VA, n. NC, and n. TN. The species is a triploid, reproducing apogamously. [= FNA, K; Thelypteris phegopteris (Linnaeus) Slosson -- RAB, C, G, W; Dryopteris phegopteris (Linnaeus) C. Christensen -- F; Phegopteris phegopteris (Linnaeus) Keyserling -- S]
Phegopteris hexagonoptera (Michaux) FJe, Broad Beech Fern. Mt, Pd, Cp (NC, SC, VA): mesic to submesic forests; common (uncommon in the Coastal Plain). April-August. Widespread in eastern North America, from QuJbec west to Ontario, WI, and MN, south to FL and e. TX. [= FNA, K, S; Thelypteris hexagonoptera (Michaux) Weatherby -- RAB, C, G, W; Dryopteris hexagonoptera (Michaux) C. Christensen -- F]
References: Smith (1981).
A genus of about 875 species, cosmopolitan, perhaps warranting separation into various segregates.
1. Leaves 5-15 (-20) cm wide; rhizome scales 1-4 mm long, lanceolate to ovate, glabrous, pale brown to golden brown, flexible and very thin...... 2
1. Leaves (6-) 10-35 cm wide; rhizome scales 2-6 mm long, linear-lanceolate, usually minutely pilose, yellowish-brown to brown, stiff and rather thick; [subgenus Cyclosorus]...... 4
4. Basal veins from adjacent lobes of the pinna not meeting at all, or reaching the sinus at the same point, thus without a united vein to the sinus...... 6
*Thelypteris dentata (ForsskDl) E. P. St. John, Downy Maiden Fern. Cp (SC): disturbed areas; rare, native to tropical and subtropical Asia and Africa. [= FNA, K, S; Christella dentata (ForsskDl) Brownsey & Jermy]
*Thelypteris hispidula (Decaisne) C.F. Reed var. versicolor (R. St. John) Lellinger, Hairy Maiden Fern. Cp (SC): on soil in disturbed areas; rare. In our area, probably only adventive from further south. [= FNA, K; Th. versicolor R. St. John -- S; Christella hispidula (Decaisne) Holttum; Th. quadrangularis (Fee) Schelpe var. versicolor (R. St. John) A.R. Smith]
Thelypteris kunthii (Desvaux) C.V. Morton, Kunth's Maiden Fern, Southern Shield Fern. Cp (NC, SC): coquina limestone ("marl') outcrops, calcareous bluffs and sinkhole slopes, also adventive on and around coquina limestone (marl) riprap around small bridges and ditches; rare (in NC, perhaps only recently adventive from further south). May-August. In North America, ranging from se. NC south to FL and west to TX. [= RAB, FNA, K; Th. normalis (C. Christensen) Moxley -- S; Christella normalis (C. Christensen) Holttum]
Thelypteris noveboracensis (Linnaeus) Nieuwland, New York Fern. Mt, Pd, Cp (NC, SC, VA): mesic forests, bottomland forests, bogs, submesic forests; common. May-August. Ranging from Newfoundland and WI south to GA, AL, and AR. Distinctive in the leaves tapering about equally both to tip and base. [= RAB, C, FNA, G, K, S, W; Dryopteris noveboracensis (Linnaeus) A. Gray -- F; Parathelypteris noveboracensis (Linnaeus) Ching]
Thelypteris ovata R. P. St. John var. ovata, Ovate Maiden Fern. Cp (SC): on coquina limestone ("marl") or in disturbed, calcareous areas; rare. Ranging from s. SC south to s. FL, west to s. AL; and in the Bahamas. In our area, perhaps only adventive from further south. Var. lindheimeri (C. Christensen) A.R. Smith occurs in TX, Mexico, Belize, Guatemala, and Jamaica. [= FNA, K, S; including Th. ovata var. harperi (C. Christensen) R. P. St. John -- S; Christella ovata (R.P. St. John) L`ve & L`ve]
Thelypteris palustris Schott var. pubescens (Lawson) Fernald, Marsh Fern. Mt, Pd, Cp (NC, SC, VA): bogs, marshes, and bottomland forests; common. June-September. The species is circumboreal, occurring in n. Europe, n. Asia, and n. North America. Var. pubescens is the American variety, ranging from Newfoundland and Manitoba south to FL and TX. [= C, FNA, G, K, W; Th. palustris -- RAB; Dryopteris thelypteris (Linnaeus) Swartz var. pubescens (Lawson) A.R. Prince ex Weatherby -- F; Th. thelypteris (Linnaeus) Nieuwland -- S]
Thelypteris simulata (Davenport) Nieuwland, Bog Fern, Massachusetts Fern. Mt (NC), Cp (VA): in NC in acid peat bogs at about 1000 meters in elevation, in VA in acid seepage swamps in the Coastal Plain; rare (NC Threatened, VA Rare List). July-September. Northeastern, ranging from Nova Scotia south to ne. VA (Accomack, New Kent, Northampton and Westmoreland counties) and n. WV (Tucker and Preston counties), and disjunct in NC (Alleghany and Avery counties) and WI. Discovered in NC in the 1980's. Presently known in NC only from two sites. [= C, FNA, G, S, W; Dryopteris simulata Davenport -- F; Parathelypteris simulata (Davenport) Holttum]
Thelypteris is a large and rather heterogeneous group, even with the removal of Phegopteris and Macrothelypteris. Our species fall into 3 subgenera, sometimes treated as genera: subgenus or genus Thelypteris (T. palustris var. pubescens), subgenus or genus Parathelypteris (T. noveboracensis, T. simulata), subgenus Cyclosorus or genus Christella (T. dentata, T. hispidula var. versicolor, T. kunthii, T. ovata var. ovata). The appropriate names, should the segregate genera be adopted, are listed in synonymy.
Thelypteris pilosa (M. Martens & Galeotti) Crawford var. alabamensis Crawford is a narrow endemic of moist sandstone rocks in nc. AL; var. pilosa is distributed in Mexico and Central America. This rare fern should be sought more widely, including in our area. It differs from all our species in having elongate sori (vs. round to slightly oblong), sporangia with minute puberulence (vs. glabrous), and small (less than 20 cm long) evergreen leaf blades. It is in a fourth group (see discussion above), subgenus or genus Stegnogramma. If Stegnogramma is accepted as a genus, the name for this plant is Stegnogramma pilosa (M. Martens & Galeotti) K. Iwatsuki var. alabamensis (Crawford) K. Iwatsuki.
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.