Click the number at the start of a key lead to highlight both that lead and its corresponding lead. Click again to show only the two highlighted leads. Click a third time to return to the full key with the selected leads still highlighted.
1 Gametophytes only present; [subfamily Vittarioideae] |
|
2 Leaves undissected and unlobed, linear, 10-60 cm long and 1-3 mm wide; [subfamily Vittarioideae] |
2 Leaves dissected, not linear, > 20 mm wide. |
3 Sori round or oblong, distinct and separate along the pinnule margins; leaves bright-green, glabrous, herbaceous, delicate, and flexible (darker green, thicker, and hairy in A. hispidulum); [subfamily Vittarioideae] |
3 Sori continuous along the pinnule margins (or across the blade in Acrostichum); leaves mostly dark-green or glaucous, often pubescent, coriaceous, tough, and stiff (except Ceratopteris). |
4 Plant aquatic or subaquatic, pale green, delicate; [subfamily Ceratopteridoideae] |
4 Plant epipetric or terrestrial (except Acrostichum), usually dark or bluish green and coriaceous. |
5 Fertile pinnae with entire lower surface covered by sporangia; leaves 1.5-5 m long; [of wetlands, n. FL southward]; [subfamily Ceratopteridoideae] |
5 Fertile pinnae with sori marginal; leaves < 0.5 m long; [of rocky sites, collectively widespread]. |
6 Leaves strongly dimorphic, the fertile leaves obviously longer than the sterile and with narrow elongate ultimate segments; [subfamily Cryptogrammoideae] |
6 Leaves essentially monomorphic. |
7 Petioles with alternating longitudinal grooves (2 or 3) and ridges on the upper surface; [subfamily Pteridoideae]. |
8 Lower surface of leaf blades with white or yellow farina; sporangia along the veins, not covered by the reflexed leaf margin; [of peninsular FL in our region] |
8 Lower surface of leaf blades lacking farina; sporangia submarginal, typically covered by the reflexed leaf margin; [widespread in our region] |
7 Petioles rounded, flattened, or with a single groove on the upper surface; [subfamily Cheilanthoideae]. |
9 Leaves 1- pinnate or 1- pinnate- pinnatifid; lower leaf blade surfaces densely covered with stellate and ciliate- fringed scales; petiole with 2 vascular bundles |
9 Leaves 1- pinnate- pinnatifid or more divided (to 5- pinnate); lower leaf blade surfaces glabrous to pubescent and/or farinose; petiole with 1 vascular bundle. |
10 Lower leaf surface with dense white farina. |
11 Leaf blade deltoid; white farina on lower blade surface not interspersed with shiny, dark-brown needle-like hairs; [of KY westwards] |
11 Leaf blade lanceolate; white farina on lower blade surface interspersed with shiny, dark-brown needle-like hairs; [of s. TX only in our region] |
10 Lower leaf surface not farinose, variously glabrous or hairy; [widespread in our region]. |
12 Leaf blade pentagonal in outline, divided into 3-5 segments which are each merely pinnatifid |
12 Leaf blade lanceolate or ovate in outline, 1-5- pinnate. |
13 Leaves 1-3- pinnate, the ultimate leaf-segments 8-100 mm long, glabrous or sparsely and inconspicuously hairy |
14 Petioles slightly grooved or flattened and ultimate segments thin in texture and not strongly rolled, and also lacking a mucro or cusp at apex |
14 Petioles either terete (not grooved/flattened), or petiole flattened, and then the ultimate segments also leathery and strongly rolled and with mucronate apex |
13 Leaves 2-5- pinnate, the ultimate leaf-segments 1-4 (-8) mm long, more-or-less densely hairy ( glabrous or glabrescent in Myriopteris alabamensis and M. microphylla). |
15 Ultimate leaf segments cordate at the base and well-separated from one another on prominent stalks [of ec. TX only in our region] |
15 Ultimate leaf segments never cordate, approximate to one another |
1 Leaves pinnatifid or bipinnatifid, the pinnae not fully divided from one another (the rachis winged by leaf tissue most or all of its length). |
2 Leaves pinnatifid, the pinnae not lobed. |
3 Leaf blades with a long- attenuate apex, blade lobed for up to 2/3 its length; sori elongate |
3 Leaves without a long- attenuate apex, blade lobed for > 4/5 of its length; sori round |
2 Leaves bipinnatifid, at least the lowermost pinnae deeply lobed. |
4 Leaves of a very delicate texture, 1 cell thick; sori borne in cups on the leaf margins; [rock outcrops with high air humidity] |
4 Leaves of an herbaceous, subcoriaceous, or coriaceous texture, > 1 cell thick; sori otherwise; [various habitats, not strictly of moist sites]. |
5 Leaf blades 1-7 cm long, hairy with some hairs > 1 mm long |
5 Leaf blades > 7 cm long, glabrescent or hairy with hairs < 1 mm long. |
6 Lowermost (and other) pinnae with numerous, rather even lobes |
|
1 Leaves pinnate, pinnate- pinnatifid, 2- pinnate, or even more divided, to 5- pinnate (the rachis naked for most of its length, often winged in the apical portion). |
|
8 Leaves of a very delicate texture, 1 cell thick; sori borne in cups on the leaf margins; [rock outcrops with high air humidity] |
8 Leaves of an herbaceous, subcoriaceous, or coriaceous texture, > 1 cell thick; sori otherwise or sporangia not grouped in sori; [various habitats, not strictly of moist sites]. |
9 Pinnae > 1 cm wide; leaves subcoriaceous to coriaceous |
10 Sporangia borne on 2 specialized fertile pinnae (in rows on segments of the 2 basalmost fertile pinnae of the leaf); [native; TX westwards] |
10 Sporangia borne on the lower surface of green leaves; [collectively widespread] |
11 Veins free; [native; s. FL] |
11 Veins anastamosing (rejoining one another) to form a netlike pattern of areoles. |
12 Costae with a groove on the upper side, sometimes with tan, filiform scales; margins of segments denticulate, crenate, or spinulose |
12 Costae rounded or flat on the upper side, with red, multicellular hairs; margins of segments entire or with rounded lobes |
9 Pinnae < 1 cm wide; leaves herbaceous to subcoriaceous. |
13 Sori on the undersurface of the leaf, located away from the margins |
13 Sori on the undersurface of the leaf, marginal and more-or-less hidden beneath either the unmodified revolute leaf margin or under a modified, reflexed false indusium |
7 Leaves bipinnate or more divided. |
14 Leaf blade pentagonal, broadly triangular, or narrowly triangular in outline, ca. 1-2.5× as long as wide. |
15 Leaf blade narrowly triangular in outline, mostly 2-2.5× as long as wide. |
16 Sporangia borne either in many sori on fertile blades or on fertile pinnules borne at the base of the otherwise sterile blades |
16 Sporangia borne in a solitary sorus terminal on the truncate apex of wedge-shaped leaf segments |
15 Leaf blade either ovate, pentagonal, or broadly triangular in outline, mostly 0.8-2× as long as wide. |
17 Leaves dimorphic, fertile leaves with longer and narrower segments than the sterile leaves |
|
18 Leaf segments strongly revolute; sporangia scattered along veins or submarginal, not grouped into indusiate sori; lower surface of leaf segments either densely covered with a whitish farina or distinctly bluish-green |
18 Leaf segments planar; sporangia borne in round, indusiate sori; lower surfaces of leaf segments green. |
19 Leaf blade pentagonal in outline, the terminal pinna by far the largest; rhizome 5-8 mm in diameter; indusia present, thick, persistent, and reniform; [introduced species, rarely naturalized] |
19 Leaf blade broadly triangular in outline, the basal pinnae by far the largest; rhizome ca. 1 mm in diameter; indusia absent; [native species of mountain peaks from n. NC and VA northwards] |
14 Leaf blade elongate, mostly lanceolate, generally > 4× as long as wide (except in Adiantum, with leaf blade often only 1.5-3× as long as wide, but not notably triangular or pentagonal in outline). |
20 Sori marginal, usually more-or-less hidden under the revolute margin of the pinnule |
20 Sori not marginal, either exposed, or slightly to strongly hidden by indusia. |
21 Leaf blades 3-12 cm long; sori elongate, covered by a flap-like, entire indusium |
21 Leaf blades 4-30 (-50) cm long; sori globular, surrounded or covered by an entire, ciliate, or divided indusium. |
22 Veins reaching the margin; indusium attached under one side of the sorus, hood-like or pocket-like, arching over the sorus; petioles glabrous or sparsely beset with scales, the petiole bases not persistent |
22 Veins ending short of the margin; indusium attached under the sorus, either cup-like (divided into 3-6 lanceolate to ovate lobes which surround the sorus from below) or of minute numerous septate hairs, which extend out from under the sorus on all sides; petioles often densely beset with scales, the petiole bases persistent |
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. |
|
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. |
|
|
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 |
|
|
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). |
|
|
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 |