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 or ascending, frequently branched;

scales dark reddish brown to blackish throughout, narrowly deltate, 2–4 × 0.2–0.4 mm, margins entire to undulate or with widely spaced shallow teeth.

monomorphic.

monomorphic.

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

indument of black filiform scales.

reddish brown at base, green distally, lustrous, 1–5(–6) cm, 1/4–1/2(–1) times length of blade;

indument of dark reddish brown to black, narrowly deltate scales grading into glandular hairs.

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

base gradually tapered;

apex acute, not rooting.

linear, 1-pinnate throughout, 2–13 × 0.6–1.2 cm, thin, glabrous or with sparse minute hairs;

base slightly tapering or truncate;

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 6–21 pairs, deltate to rhombic;

medial pinnae 5–6 × 4–5 mm;

base obtuse and often inequilateral;

distal margins crenate;

apex rounded to acute.

free, obscure.

free, evident.

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

2–4 pairs per pinna, on both basiscopic and acroscopic sides.

32 per sporangium.

64 per sporangium.

reddish brown throughout, lustrous, glabrous.

green throughout, dull, glabrous or with scattered hairs as on petioles.

= 2n = 108 (apogamous).

= 72.