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

2.5–20 × 0.5–2.5 cm.

9–35 × 1–8 cm.

reddish brown or dark purple when mature, articulate above base at swollen node, relatively brittle and easily shattered.

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

linear to narrowly lanceolate, usually pinnate-pinnatifid proximally, lacking glands, never viscid;

rachis with widely scattered hairs and scales.

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.

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

largest pinnae with 1–3 pairs of pinnules;

abaxial surface with isolated hairs and linear scales, adaxial surface glabrous.

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.

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

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

averaging 46–53 µm.

averaging 39–57 µm.

entire or broadly crenate;

margins nonlustrous, thin, with occasional isolated cilia, lacking translucent projections.

dentate, often shallowly lobed;

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

tips often enlarged to form whitish hydathodes visible adaxially.

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