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, not branched;

scales blackish throughout or rarely with narrow pale margins, narrowly linear, mostly only 8–12 cells wide proximally, 2–3 × 0.5–0.8 mm.

monomorphic.

monomorphic.

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

indument of black filiform scales.

blackish to greenish, dull, 1–7(–17) cm, 1/5–1/2 length of blade; glabrous with few scales at base.

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

base gradually tapered;

apex acute, not rooting.

oblong-lanceolate, 2–3-pinnate, (2–)6–12(–18) × 2.7–10 cm, thin, glabrous;

basal pinna pairs unreduced to reduced 1/4;

apex gradually reduced, 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 (7–)10–15(–20) pairs, oblong, 2-pinnate throughout;

medial pinnae (1–)2–3(–6) cm, all ± curved upward;

proximal pinnae descending;

base cuneate;

apex attenuate.

free, obscure.

free, evident.

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

1–4(–6) per pinnule, usually on both basiscopic and acroscopic sides.

32 per sporangium.

64 per sporangium.

reddish brown throughout, lustrous, glabrous.

blackish, dull, glabrous.

= 2n = 108 (apogamous).

± asymmetric, 1–5(–10) × 1–4 mm;

margins strongly dentate, cut 1/3–1/2 to axis.

= 72.