Flora of North America species comparison

compact, erect to ascending, with abundant persistent petiole bases of ± equal length;

scales uniformly brown, 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.

4.5–25 × 1.2–3.5 cm.

4–30 × 1.5–6 cm.

usually brown or dark purple when mature, articulate above base at swollen node, 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.

narrowly lanceolate, usually 2-pinnate proximally, lacking glands, never viscid;

rachis usually with abundant hairs and scales.

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.

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

largest pinnae with 4–9 pairs of pinnules;

abaxial surface with mixture of hairs and linear-lanceolate scales, adaxial surface with multicellular hairs concentrated along midrib.

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 narrow, hairlike segments, these uniseriate throughout, composed of cells many times longer than wide, usually surpassing mature sporangia.

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

averaging 39–46 µm. 2n = 82.

averaging 44–52 µm. 2n = 152.

entire or crenate, rarely shallowly lobed;

margins nonlustrous, thin, ciliate with 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 frequently enlarged to form whitish hydathodes visible adaxially.

tips occasionally enlarged to form whitish hydathodes visible adaxially.