Flora of North America species comparison

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

scales uniformly brown, lanceolate.

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.

3.5–15 × 0.5–1.2 cm.

5–35 × 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.

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.

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.

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, often greatly surpassing mature sporangia.

averaging 39–45 µm. 2n = 78.

averaging 37–44 µm. 2n = 76.

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 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.

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

tips usually enlarged to form whitish hydathodes visible adaxially.