Flora of North America species comparison

not proliferous.

proliferous.

erect, unbranched;

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

erect, unbranched;

scales blackish throughout, linear, 0.9–1.1 × 0.2–0.3 mm, margins entire.

monomorphic.

dimorphic;

sterile leaves short with small crowded pinnae;

fertile leaves 9–20 cm with long, widely spaced pinnae.

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

indument of black filiform scales.

pale green except darkish proximally, dull, (1–)4–6(–10) cm, 1/5–1/2 length of blade;

indument absent.

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

base gradually tapered;

apex acute, not rooting.

linear, 1-pinnate, 3–10(–15) × 1–2.5 cm, papery, slightly glandular;

base not tapered;

apex with elongate terminal pinna similar in size to subtending lateral pinnae, 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 5–8(–12) pairs, ovate, strongly asymmetric, lanceolate;

medial pinnae 3–11 × (2–)4–6 mm;

base acute;

margins crenate-dentate;

apex truncate.

free, obscure.

free, somewhat evident.

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

(1–)2–5(–8), mostly on acroscopic side.

32 per sporangium.

64 per sporangium.

reddish brown throughout, lustrous, glabrous.

green throughout, dull, glabrous.

= 2n = 108 (apogamous).

= 108.