Flora of North America species comparison

not proliferous.

proliferous.

erect, unbranched;

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

erect, unbranched;

scales blackish throughout, linear to narrowly triangular, 0.9–1.3 × 0.1–0.4 mm, margins entire.

monomorphic.

monomorphic.

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

indument of blackish brown, filiform scales.

brownish black, 0.5–3(–5) cm, 1/9–1/7 length of blade;

indument of blackish, linear-lanceolate scales at base.

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

base gradually tapered;

apex acute, not rooting.

narrowly lanceolate, 2–3-pinnate, (4–)10–20(–)30 × 1–3(–5) cm, thin, glabrous;

base tapered somewhat;

apex formed by gradual reduction, not rooting.

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.

in (8–)12–16(–22) pairs, oblong;

medial pinnae 0.5–2.5 × 3–10 mm;

base cuneate;

apex obtuse.

free, obscure.

free, evident, 1 per segment.

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

1 per segment.

32 per sporangium.

64 per sporangium.

black throughout, lustrous, glabrous.

blackish brown, dull, essentially glabrous.

= 2n = 108 (apogamous).

of 1–5 segments;

segments oblanceolate, 2–3 × 1–2 mm, entire;

apex mostly round.

= 144.