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 or ascending, rarely branched;

scales black throughout, linear-lanceolate, 2–3 × 0.2–0.4 mm, margin entire, apex attenuate.

monomorphic.

monomorphic.

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

indument of black filiform scales.

black or purplish black throughout, lustrous, 0.3–5 cm, 1/4–1/15 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 or narrowly oblanceolate, 1-pinnate throughout, 6–22(–37) × 1–1.8(–2.3) cm, thin, glabrous;

base 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 15–40 pairs, oblong;

medial pinnae somewhat asymmetric, oblong, 4–10 × 2–4(–5) mm;

base acute, acroscopically enlarged;

margins serrate to crenate, lobed;

apex obtuse.

free, obscure.

free, evident.

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

3–6 pairs per pinna, on both basiscopic and acroscopic sides of pinnae.

32 per sporangium.

64 per sporangium.

reddish brown throughout, lustrous, glabrous.

black throughout, lustrous, glabrous.

= 2n = 108 (apogamous).

= 144, 216.