Flora of North America species comparison

not proliferous.

not proliferous.

short-creeping or ascending, frequently branched;

scales dark reddish brown to blackish throughout, narrowly deltate, 2–4 × 0.2–0.4 mm, margins entire to undulate or with widely spaced shallow teeth.

ascending to erect, rarely branched;

scales dark brown to blackish throughout, narrowly deltate, 2–4 × 0.25–0.45 mm, margins entire.

monomorphic.

weakly subdimorphic, fertile leaves taller and more erect than sterile leaves.

reddish brown at base, green distally, lustrous, 1–5(–6) cm, 1/4–1/2(–1) times length of blade;

indument of dark reddish brown to black, narrowly deltate scales grading into glandular hairs.

reddish or purplish brown throughout, lustrous, 1–10 cm, 1/5–1 times length of blade;

indument of dark brown to black scales, narrowly deltate at very base, grading into hairs distally.

linear, 1-pinnate throughout, 2–13 × 0.6–1.2 cm, thin, glabrous or with sparse minute hairs;

base slightly tapering or truncate;

apex acute, not rooting.

highly variable and typically irregularly shaped, narrowly deltate to lanceolate, pinnatifid or 1-pinnate in proximal 1/3, 2–20 × 1–6(–13) cm, medium thick, sparsely pubescent adaxially only;

base ± truncate;

apex acute to long-attenuate, apical buds borne occasionally but not known to root in nature.

in 6–21 pairs, deltate to rhombic;

medial pinnae 5–6 × 4–5 mm;

base obtuse and often inequilateral;

distal margins crenate;

apex rounded to acute.

in 0–3 pairs, often irregular in size and shape, deltate to narrowly deltate;

proximal pinnae 5–30(–80) × 3–10(–15) mm;

base truncate to obtuse, auriculate on both sides;

margins entire to finely serrate or crenulate;

apex obtuse to acute or occasionally attenuate.

free, evident.

somewhat evident, mostly free, rarely anastomosing.

2–4 pairs per pinna, on both basiscopic and acroscopic sides.

1–10(–15+) pairs per pinna, on both acroscopic and basiscopic lobes.

64 per sporangium.

malformed (sterile form) or 64 per sporangium (fertile form).

green throughout, dull, glabrous or with scattered hairs as on petioles.

reddish or purplish brown abaxially, fading to green distally, lustrous, glabrous.

= 72.

= 72, 144.