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 black with pale margins, linear, extremely narrow, 2–3 mm, only several cells wide.

monomorphic.

monomorphic.

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

indument of black filiform scales.

green in small leaves, black abaxially and green adaxially in large leaves, (1–)2–7(–16) cm, 1–2 times length of blade;

indument of fine, nonglandular hairs on veins.

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

base gradually tapered;

apex acute, not rooting.

deltate, simple to 2-pinnate, 1–8(–12) × 1–6(–8) cm, thin, papery with scattered hairs on both surfaces;

base truncate;

margins crenate-dentate;

apex pointed, 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 0–5 pairs, ovate to deltate, simple to lobed to pinnate proximally, 1–6 × 1–3.5 cm, proximal pinna pair largest;

base broadly cuneate to truncate;

margins irregularly crenate;

apex rounded to pointed.

free, obscure.

free, evident.

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

1–15(–35) per pinna, on both basiscopic and acroscopic sides.

32 per sporangium.

64 per sporangium.

reddish brown throughout, lustrous, glabrous.

green, dull, glabrous.

= 2n = 108 (apogamous).

= 72.