Flora of North America species comparison

creeping for 2–5 cm, then ascending or suberect, 1.5–3 mm diam.

creeping to erect, scaly at apex.

monomorphic, dying back in winter, tightly clustered, (25–)40–105 cm.

monomorphic or somewhat dimorphic [dimorphic].

straw-colored, 3–20(–35) cm × 1–3 mm, at base with scales tan to reddish brown, ovate, glabrous.

in cross section with 2 crescent-shaped vascular bundles at base.

elliptic, 20–70 cm, proximal 4–10 pinna pairs gradually reduced (smallest 5–20 mm), blade tapering gradually to pinnatifid apex.

pinnate to pinnate-pinnatifid, rarely more than 2-pinnate [simple];

rachis grooved adaxially or not, grooves not continuous with grooves of next order.

3–10 × (0.6–)1–2 cm, deeply pinnatifid to within 1 mm of costa;

segments oblong to linear, oblique (sides slanted, not perpendicular to costa), entire to crenulate;

proximal pair of veins from adjacent segments meeting margin above sinus.

free or anastomosing, running to margin, areoles with or without included free veinlets.

round, supramedial;

indusia tan, glabrous or short-ciliate, sometimes also with glands;

sporangia glabrous.

inframedial to supramedial, occasionally nearly marginal, round or oblong, rarely elongate along veins;

indusia reniform or sometimes absent.

bilateral, monolete [rarely globose-tetrahedral and trilete], usually with a prominent, crested, echinate, or reticulate perispore.

green, cordate, usually hairy or glandular;

antheridia 3-celled.

abaxially of sparsely set hairs 0.2–0.7 mm on rachises, costae, and sometimes veins, also of numerous orangish, sessile to usually short-stalked glands on blade tissue;

blades adaxially glabrous except along costae.

of transparent, needlelike, hooked, septate, or stellate hairs, or rarely hairs lacking.

= 54.