Flora of North America species comparison

not proliferous.

proliferous.

short-creeping, often branched;

scales black throughout or with brown borders, lanceolate, 2–5 × 0.2–0.5 mm, margins entire to denticulate.

erect, unbranched;

scales brown throughout, broadly linear, 1–2 × 0.7–1.1 mm, margins shallowly and widely dentate.

monomorphic.

monomorphic.

reddish brown or blackish brown throughout, lustrous, 1–4(–7) cm, 1/6–1/4 length of blade;

indument absent or of black, linear-lanceolate or filiform scales at base.

green to black, dull, 2–10(–12) cm, 1/3–1/2 length of blade;

indument absent.

linear, 1-pinnate, 3–22 × 0.5–1.5 cm, thin, glabrous or sparsely pubescent;

base gradually tapered;

apex narrowly acute, not rooting.

narrowly deltate, 1–2-pinnate, 4–20(–30) × 1.8–12(–18) cm, thick, nearly glabrous;

base not tapered;

apex gradually tapered, not rooting.

in 15–35 pairs, oblong to oval;

medial pinnae 2.5–8 × 2.5–4 mm;

base broadly cuneate, with or without low, rounded acroscopic auricle;

margins shallowly crenate to serrate or ± entire;

apex obtuse.

in 10–22 pairs, linear-deltate, medial pinnae 1–4(–9) × 0.3–1(–2.5) cm;

base with acroscopic auricle or pinnule enlarged, excavated in proximal 1/5–1/4;

margins mostly 1–2-dentate-serrate, or lobed or pinnate proximally or in proximal 2/3;

apex blunt in some 1-pinnate forms, gradually reduced to attenuate in strongly 2-pinnate forms;

pinnules narrow, not auriculate.

free, evident.

free, evident.

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

4–9(–10) pairs per pinna, subcostal, nearly parallel to costae on both basiscopic and acroscopic sides.

64 per sporangium.

64 per sporangium.

reddish brown throughout, lustrous, glabrous or nearly so.

green to black, dull, abaxially glabrous.

= 72, 144.