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.

short-creeping, unbranched;

scales black with lighter margins, linear-lanceolate, 1.5–3 × 0.1–0.4 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.

purplish black, lustrous, 0.5–3 cm, 1/3–1/20 length of blade;

indument of black filiform scales at base.

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

base gradually tapered;

apex acute, not rooting.

linear, 1-pinnate throughout, 7–17.5 × 0.9–1.8 cm, thick, glabrous;

base gradually reduced;

apex gradually reduced to whiplike rooting tip.

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 (12–)20–40 pairs, oblong;

medial pinnae 6–9 × 3–4 mm;

base broadly cuneate or auriculate;

margins crenate-serrate;

apex obtuse.

free, obscure.

free, obscure.

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

3–7 pairs per pinna, on both basiscopic and acroscopic sides.

32 per sporangium.

64 per sporangium.

reddish brown throughout, lustrous, glabrous.

purplish black throughout, lustrous, glabrous or nearly so.

= 2n = 108 (apogamous).