Flora of North America species comparison

compact to short-creeping, erect to horizontal, with few to many persistent petiole bases of unequal lengths;

scales mostly uniformly brown but at least some bicolored with dark central stripe and pale brown margins, narrowly lanceolate.

compact, erect to ascending, with a few persistent petiole bases of unequal lengths;

scales often uniformly brown but at least some bicolored with dark central stripe and pale brown margins, narrowly lanceolate.

5–35 × 1.5–6 cm.

5–25 × 1.5–6 cm.

light brown or straw-colored when mature, occasionally darker at very base, not articulate above base, relatively brittle and easily shattered.

reddish brown to dark purple when mature, not articulate above base, somewhat pliable and resistant to shattering.

lanceolate, usually 2-pinnate proximally, sparsely to moderately glandular, never viscid;

glandular hairs with thin stalks and slightly expanded tips;

rachis with scattered glandular hairs and hairlike scales.

lanceolate to ovate, usually 2-pinnate proximally, densely glandular, often somewhat viscid;

most glandular hairs with thick stalks and distinctly bulbous tips;

rachis with abundant glandular hairs and a few narrow scales.

elongate-deltate to elliptic, longer than wide, often attenuate to a narrowly acute apex;

largest pinnae with 7–18 pairs of widely spaced pinnules;

abaxial and adaxial surfaces somewhat glandular, lacking nonglandular hairs or scales.

ovate-deltate to elliptic, longer than wide, abruptly tapered to a rounded or broadly acute apex, occasionally attenuate;

largest pinnae with 5–11 pairs of pinnules;

abaxial and adaxial surfaces glandular, lacking nonglandular hairs or scales.

of narrow, filamentous segments, these uniseriate for most of length, composed of ± isodiametric cells, often greatly surpassing mature sporangia.

of relatively broad segments;

segments multiseriate for most of length, often divided and uniseriate distally, composed of ± isodiametric cells, often surpassing mature sporangia.

averaging 37–44 µm. 2n = 76.

averaging 44–50 µm. 2n = 152.

dentate, often shallowly lobed;

margins often lustrous adaxially, somewhat thickened, with occasional glands, appearing ciliate due to presence of multicellular translucent projections on teeth that are often prolonged to form twisted filaments.

dentate, often shallowly lobed;

margins nonlustrous, thin, densely glandular, lacking cilia but with occasional 1–2-celled translucent projections.

tips usually enlarged to form whitish hydathodes visible adaxially.

tips slightly (if at all) enlarged, barely visible adaxially.