Flora of North America species comparison

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

scales uniformly brown or bicolored with dark central stripe and pale brown margins, ovate to narrowly lanceolate.

compact, erect to ascending, 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.

9–35 × 1–8 cm.

4–30 × 1.5–6 cm.

usually reddish brown to dark purple proximally when mature, not articulate above base, relatively brittle and easily shattered.

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

lanceolate to linear-lanceolate, 2-pinnate proximally, moderately glandular, rarely somewhat viscid;

most glandular hairs with thick stalks and distinctly bulbous tips;

rachis usually with abundant glandular and nonglandular hairs.

linear to lanceolate, usually pinnate-pinnatifid proximally, glabrescent to sparsely glandular, never viscid;

glandular hairs with thin stalks and slightly expanded tips;

rachis with scattered glandular hairs and rare, hairlike scales.

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

largest pinnae with 5–14 pairs of pinnules;

abaxial and adaxial surfaces glandular and sparsely villous, with flattened, multicellular hairs concentrated along midribs.

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

largest pinnae with 3–7 pairs of closely spaced pinnules;

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

of filamentous or nonfilamentous segments, these multiseriate proximally, often uniseriate distally, composed of ± isodiametric cells, concealed by or slightly surpassing mature sporangia.

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

averaging 39–57 µm.

averaging 44–52 µm. 2n = 152.

dentate, often shallowly lobed;

margins nonlustrous, thin, slightly glandular and occasionally ciliate with isolated, multicellular hairs, lacking translucent projections.

dentate, often shallowly lobed;

margins nonlustrous, thin, with occasional glands, lacking cilia, with 1–2-celled translucent projections on teeth.

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

tips occasionally enlarged to form whitish hydathodes visible adaxially.