Flora of North America species comparison

not proliferous.

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, unbranched;

scales brown throughout, narrowly lanceolate, 5–10 × 1–1.5 mm, margins entire.

monomorphic.

monomorphic.

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.

vestigial.

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

base gradually tapered;

apex narrowly acute, not rooting.

linear, oblanceolate, simple, (10–)20–40(–70) × 3–8 cm, thick, glabrous;

base gradually tapered;

margins entire to irregularly crenate;

apex attenuate, not rooting.

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.

numerous, free, mostly immersed.

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

parallel to each other, nearly perpendicular to midrib.

64 per sporangium.

64 per sporangium.

reddish brown throughout, lustrous, glabrous or nearly so.

green throughout, dull, glabrous.

= 72, 144.

= 144.