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1 Leaf blades 7-25 (-30) cm long, triangular, < 2× as long as wide (or lanceolate and > 4× as long as wide in the rarely naturalized P. decursive-pinnata); rachis with adnate wings between the pinnae; sori without indusia; midribs of pinnae lacking an adaxial groove; [subfamily Phegopteridoideae]; [Phegopteroid clade] |
1 Leaf blades (15-) 20-100 cm long, lanceolate, oblong- lanceolate, or triangular, > 2× 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 Midribs of the pinnae lacking an adaxial groove; leaf bipinnate to tripinnate; [subfamily Phegopteridoideae]; [Phegopteroid clade] |
2 Midribs of the pinnae with an adaxial groove; leaf pinnate to pinnate- pinnatifid; [subfamily Thelypteridoideae. |
3 Leaves 1- pinnate (the pinnae entire or serrate, and also often undulate); veins forming parallel rows of more than 5 areoles between the pinna margin and the main vein, the areoles with a single excurrent, free veinlet; sori elongate; [Goniopteroid clade] |
3 Leaves 1- pinnate- pinnatifid (the pinnae lobed to pinnatifid); veins all free or at most with a single areole between the sinus and the main vein; sori round or reniform (elongate in Leptogramma). |
4 Stellate hairs present on rachis, veins, and upper leaf blade surface; [n. FL south to s. FL]; [Goniopteroid clade] |
4 Stellate hairs absent; [collectively widespread]. |
5 Sori elongate; sporangia with hairs 0.1-0.2 mm long; [ endemic to nc. AL]; [Stegnogrammoid clade] |
5 Sori round or slightly longer than wide; sporangia glabrous; [collectively widespread]. |
6 Basal veins from adjacent lobes of the pinna not meeting at all; lowermost pinnae pinnae of a leaf either as long as the pinnae above (or only slightly smaller), or strongly reduced (with an obvious and strong taper of the blade outline towards the base). |
7 Lowermost pinnae of a leaf strongly reduced, at least 3 or 4 pairs distinctly smaller than the longest pair on a leaf (and therefore with an obvious and strong taper of the blade outline towards the base); [Amauropeltoid clade]. |
7 Lowermost pinnae of a leaf as long as the pinnae above, or only slightly smaller (> 80% as long). |
8 Veins of the pinna-lobes unbranched; lower leaf surface with sessile, reddish, resinous glands; lower surface of costae lacking scales; [ montane w. NC and e. TN northeastwards]; [Amauropeltoid clade] |
8 Veins of the pinna-lobes mostly Y- forked; lower leaf surface lacking glands; lower surface of costae with persistent ovate scales; [widespread in our region]; [Thelypteroid clade]. |
6 Basal veins from adjacent lobes of the pinna either uniting either below the sinus (between the sinus and the costa) and therefore forming a united vein continuing to the sinus, or reaching the sinus at the same point; lowermost pinnae of a leaf as long as the pinnae above, or only slightly smaller (> 80% as long) (except in Christella); pinnae 3.5-45 cm long, usually at least the longer > 15 cm long (except in Christella). |
9 Basal veins from adjacent lobes of the pinna reaching the sinus at the same point (but not uniting to form a united vein to the sinus); rhizomes 3-6 mm in diameter. |
10 Lower leaf surface with sessile, opaque, sulfur-colored or pale yellow glands (obvious without magnification); [Sphaerostephanoid clade] |
10 Lower leaf surface lacking sessile glands (sometimes short- stipitate light yellowish glands present) |
9 Basal veins from adjacent lobes of the pinna uniting below the sinus (between the sinus and the costa) and therefore forming a united vein continuing to the sinus (this easiest to see on the upper surface of the leaf); rhizomes 3-12 mm in diameter. |
11 Lowermost pinnae reduced, smaller than some of those above; costae abaxially lacking scales; blades abaxially lacking glands or with short- stipitate, light yellow or orangish glands; rhizomes relatively short-creeping, brown, scaly; ]Pseudocyclosoroid clade] |
11 Lowermost pinnae the longest or nearly so; costae abaxially with ovate scales; blades abaxially with sessile orangish or reddish, hemispherical glands; rhizomes very long-creeping, blackish, nearly naked; [Goniopteroid clade] |
1 Leaf vine-like, 0.3-10 m long, the branching dichotomous, 1 branch of each dichotomy terminating in a pair of pinnae, the pinnae often widely spaced (> 10 cm apart) |
1 Leaf not vine-like, 0.3-3 m long, the branching not as described above, the pinnae regularly and more-or-less closely spaced (mostly < 10 cm apart). |
2 Leaves (at least the sterile leaves if the leaves are dimorphic) 1- pinnate- pinnatifid or less divided (the pinnae entire, toothed, lobed or pinnatifid). |
3 Leaves dimorphic, the sterile leaves 1- pinnate, the fertile leaves bipinnate; sori covering the entire undersurface of the fertile leaves |
3 Leaves monomorphic; sori not covering the undersurface of the leaves. |
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4 Sori neither marginal nor continuous, slightly to entirely covered by an elongate or roundish indusium (sometimes ciliate, toothed, or divided into narrow segments); pinnae usually at least in part alternate, mostly lanceolate, toothed, lobed, or pinnatifid. |
5 Sori elongate, the indusium flap-like, attached along the side; leaf blades < 7 cm wide when > 30 cm long |
5 Sori circular or globular, the indusium peltate, reniform, or cuplike; leaf blades > 5 cm wide when > 30 cm long. |
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7 Leaves 1- pinnate, the pinnae toothed and each with a slight to prominent lobe near the base on the side toward the leaf tip; indusia peltate, reniform, or crescent-shaped. |
8 Leaves pale green, thin in texture; pinnae articulate to rachis, deciduous with age; rhizome bearing elongate, thin, wiry stolons; indusia reniform or crescent-shaped |
8 Leaves dark-green, subcoriaceous to coriaceous; pinnae not articulate and deciduous with age; rhizome not producing stolons; indusia peltate |
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7 Leaves 1- pinnate- pinnatifid or 2- pinnatifid, the pinnae pinnatifid, generally lacking a prominent basal lobe; indusia either reniform or cuplike. |
10 Vascular bundles in the petiole 3-7 |
10 Vascular bundles in the petiole 2. |
11 Indusium reniform, arching over the sorus |
11 Indusium cuplike, attached beneath the sorus and consisting of 3-6 lanceolate to ovate segments |
2 Leaves (at least the sterile leaves if the leaves are dimorphic) 2- pinnate or more divided (the pinnae divided to their midribs). |
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13 Sori marginal and borne on the underside of the false indusium (modified, marginal flaps of the leaf margin); petioles and rachis shiny black or reddish-black; pinnules fan-shaped or obliquely elongate |
13 Sori not marginal, borne on the undersurface of the leaf blade (if marginal, as in Pteridium and Dennstaedtia, borne on the undersurface of the leaf); petioles darkened only basally (if at all), rachis green, tan, or reddish; pinnules not notably fan-shaped or obliquely elongate. |
14 Outline of leaf blade narrowed to base, the widest point > 7 pinna pairs above the base, the lowermost pinnae < 1/4 as long as the longest pinnae; rhizomes long-creeping, the leaves scattered or in small tufts, forming clonal patches |
14 Outline of the leaf blade slightly if at all narrowed to the base, the widest point < 5 pinna pairs from the base, the lowermost pinnae > 1/2 as long as the longest pinnae; rhizomes short-creeping, the leaves clustered, not forming clonal patches (or with rhizomes long-creeping, leaves scattered, forming clonal patches in Dennstaedtia in DENNSTAEDTIACEAE). |
15 Rhizomes long-creeping, leaves scattered, forming clonal patches; vascular bundles in the petiole 1, U-shaped (even in the lower petiole); sori very small, marginal in sinuses, the indusium cup-like, 2-parted, the outer part a modified tooth of the leaf blade; leaf blades conspicuously puberulent with septate glandular hairs |
15 Rhizomes short-creeping, the leaves clustered, not forming clonal patches; vascular bundles in the petiole 2-7 (sometimes uniting to 1 in the upper petiole); sori mostly larger, mostly not marginal, the indusium not as above (though cup-like in Woodsia obtusa); leaf blades either glabrous, glabrescent, with flattened scales, or puberulent with glandular trichomes. |
16 Vascular bundles (3-) 5 (-7) in the petiole |
16 Vascular bundles 2 in the petiole (or uniting near the leaf blade into 1). |
17 Leaves 25-65 cm wide, with whitish, straight, acicular hairs; [species adventive and weedy] |
17 Leaves 5-25 (-30) cm wide, with scales and minute glands (sometimes also with septate hairs); [native species]. |
18 Leaves 1- pinnate- pinnatifid; indusium cup-like, attached beneath the sorus and consisting of 3-6 lanceolate to ovate segments |
18 Leaves 2- pinnate- pinnatifid; indusium flap-like, pocket-like, or hood-like, attached at one side of the sorus and arching over it. |
19 Leaves 10-30 cm wide, the tip acute to acuminate; indusium flap-like |
19 Leaves 4-9 cm wide, the tip long- attenuate; indusium pocket-like or hood-like |