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, unbranched;

scales black throughout, narrowly deltate, 2–3 × 0.2–0.3 mm, margins mostly with widely spaced, shallow teeth.

monomorphic.

monomorphic.

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

indument of black filiform scales.

dark reddish brown throughout, dull, 1–3 cm, 1/10–1/6 length of blade;

indument of black filiform scales.

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

base gradually tapered;

apex acute, not rooting.

lanceolate, 2-pinnate to 2-pinnate-pinnatifid, 4–10 × 1–3 cm, thin, sparsely pubescent;

base tapering;

apex acute to acuminate, often bearing minute, scaly, proliferous bud.

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.

10–20 pairs, narrow, oblong;

medial pinnae 5–12 × 4–7 mm;

base acute to obtuse;

margins coarsely incised;

apex notched, bearing proliferous bud.

free, obscure.

free, obscure.

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

1–4 pairs per pinna, on both basiscopic and acroscopic sides.

32 per sporangium.

64 per sporangium.

reddish brown throughout, lustrous, glabrous.

basally reddish brown, fading to green in distal 1/2 to 3/4, dull, sparsely pubescent and with a few filiform scales.

= 2n = 108 (apogamous).

= 72.