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, mainly unbranched;

scales black or with narrow pale borders, narrowly lanceolate, 1.5–3 × 0.2–0.4 mm, margins entire.

monomorphic.

monomorphic.

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

indument of black filiform scales.

dark reddish brown throughout, 1–4 mm;

indument of black linear scales at base.

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

base gradually tapered;

apex acute, not rooting.

linear, 1-pinnate, 2.5–14 × 0.5–1.2 cm, thick (open habitat) to herbaceous (shaded, moist habitat), essentially glabrous;

base somewhat tapered;

apex obtuse, 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 10–30 pairs, ovate to rhombic to ovate-oblong, 2.5–11 × 2–6 mm;

base truncate to shortly acute;

margins shallowly crenate (shade forms) to essentially entire (exposed forms);

apex obtuse, broadly rounded.

free, obscure.

free, evident to obscure.

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

1–3 pairs per pinna on both basiscopic and acroscopic sides.

32 per sporangium.

64 per sporangium.

reddish brown throughout, lustrous, glabrous.

reddish brown in proximal 1/2–4/5, green distally, lustrous, glabrous.

= 2n = 108 (apogamous).

= 144.