Flora of North America species comparison

compact, erect to ascending, with cluster of 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.

3.5–15 × 0.5–1.2 cm.

4–30 × 1.5–6 cm.

green or straw-colored throughout, articulate above base at swollen node, somewhat pliable and resistant to shattering.

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

linear to linear-lanceolate, pinnate-pinnatifid proximally, glabrous or with occasional sessile glands, never viscid;

rachis glabrous.

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-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 39–45 µm. 2n = 78.

averaging 44–52 µm. 2n = 152.

pinnae fan-shaped, wider than long;

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

largest pinnae with 1–3 pairs of pinnules, abaxial and adaxial surfaces glabrous.

entire or broadly crenate;

margins nonlustrous, thin, lacking cilia or 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.