Flora of North America species comparison

not proliferous.

not proliferous.

short-creeping, often branched;

scales black throughout or with brown borders, lanceolate, 2–5 × 0.2–0.5 mm, margins entire to denticulate.

erect or ascending, usually unbranched;

scales dark brown throughout, narrowly deltate, 2–3 × (0.2–)0.5–1 mm, margins entire.

monomorphic.

monomorphic but fertile leaves generally larger than sterile leaves.

reddish brown or blackish brown throughout, lustrous, 1–4(–7) cm, 1/6–1/4 length of blade;

indument absent or of black, linear-lanceolate or filiform scales at base.

reddish brown at base, becoming green distally, dull but sometimes lustrous at base, 0.5–12 cm, 0.1–1.5 times length of blade;

indument of dark brown, narrowly deltate scales at base, of minute, club-shaped hairs distally.

linear, 1-pinnate, 3–22 × 0.5–1.5 cm, thin, glabrous or sparsely pubescent;

base gradually tapered;

apex narrowly acute, not rooting.

highly variable in size and shape, even on 1 plant, narrowly deltate to linear-lanceolate, simple, 1–30 × 0.5–5 cm, leathery, sparsely pubescent, hairs more numerous abaxially than adaxially;

blade base cordate, auriculate, or occasionally hastate, auricles rarely attenuate and radicant;

margins entire to sinuate, rarely irregularly incised;

apex rounded to very long-attenuate and, if attenuate, generally rooting at tip.

in 15–35 pairs, oblong to oval;

medial pinnae 2.5–8 × 2.5–4 mm;

base broadly cuneate, with or without low, rounded acroscopic auricle;

margins shallowly crenate to serrate or ± entire;

apex obtuse.

free, evident.

obscure, anastomosing to form areoles near midrib.

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

numerous, scattered somewhat irregularly over blade, often joined at vein junctures.

64 per sporangium.

64 per sporangium.

reddish brown throughout, lustrous, glabrous or nearly so.

green, dull, nearly glabrous.

= 72, 144.

= 72.