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 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.

3.5–15 × 0.5–1.2 cm.

5–25 × 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 throughout 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.

narrowly lanceolate to ovate, pinnate-pinnatifid to 2-pinnate proximally, sparsely to moderately glandular, never viscid;

glandular hairs with thin stalks and slightly expanded tips;

rachis with glandular hairs and occasional hairlike scales.

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

largest pinnae with 4–9 pairs of pinnules;

abaxial and adaxial surfaces 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 relatively broad segments;

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

averaging 39–45 µm. 2n = 78.

averaging 43–49 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 lustrous adaxially, usually thickened, lacking cilia but sparsely glandular, with occasional 1–2-celled translucent projections.

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

tips enlarged to form whitish hydathodes visible adaxially.