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.

short-creeping, unbranched;

scales dark brown to black throughout, narrowly linear-deltate, 2–4 × 0.3–0.6 mm, margins entire.

monomorphic.

± dimorphic;

fertile leaves taller and more erect than sterile leaves.

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

indument of black filiform scales.

reddish brown throughout, lustrous, 1–10 cm, 1/4–1/3 length of blade;

indument of dark brown to 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.

lustrous, linear to narrowly oblanceolate, 1-pinnate throughout, 4–50 × 2–5(–7) cm, thin, glabrous, or occasionally sparsely pubescent;

base gradually 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 15–45 pairs, oblong to quadrangular;

medial pinnae 1–2.5 × 0.3–0.5 cm;

base with conspicuous acroscopic and sometimes basiscopic auricle, this overlapping rachis;

margins crenate to serrulate, sometimes more deeply incised in robust specimens;

apex acute to obtuse.

free, obscure.

free, evident.

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

1–12 pairs per pinna, on both basiscopic and acroscopic sides.

32 per sporangium.

64 per sporangium.

reddish brown throughout, lustrous, glabrous.

reddish or purplish brown throughout, lustrous, glabrous.

= 2n = 108 (apogamous).

= 72.