Flora of North America species comparison

not proliferous.

not proliferous.

erect, unbranched;

scales black with lighter margins, linear-lanceolate, 3–6 × 0.4–0.8 mm, margins entire.

erect, unbranched;

scales black throughout, linear-lanceolate, 4–5 × 0.2–0.6 mm, margins entire.

monomorphic.

monomorphic.

reddish brown throughout, lustrous, 1–12(–20) cm, 1/3–1/10 length of blade;

indument of black filiform scales.

black throughout, lustrous, 1.5–3(–5) cm, 1/4–1/10 length of blade;

indument of blackish brown, filiform scales.

linear, 1-pinnate throughout, 5–25(–40) × 1–2.5(–3) cm, thick, glabrous;

base gradually tapered;

apex acute, not rooting.

linear to narrowly oblanceolate, 1-pinnate throughout, 9–20(–30) × 1–2(–2.5) cm, thick, glabrous;

base gradually tapered;

apex acute, not rooting.

in 10–40 pairs, oblong to quadrangular, somewhat asymmetric;

medial pinnae 4–15 × 2–5 mm;

base rounded to cuneate;

margins crenulate or ± entire;

apex obtuse.

in 20–40 pairs, oblong;

medial pinnae (5–)10–20 × (2–)3–5 mm;

base usually with an acroscopic auricle;

margins ± entire to shallowly crenate;

apex obtuse.

free, obscure.

free, obscure.

1(–3) per pinna, only on basiscopic side.

2–5 pairs per pinna, on both basiscopic and acroscopic sides, often confluent with age.

32 per sporangium.

32 per sporangium.

reddish brown throughout, lustrous, glabrous.

black throughout, lustrous, glabrous.

= 2n = 108 (apogamous).

= 2n = 108 (apogamous).