Flora of North America species comparison

lacking root hairs, unbranched or with a few narrow lateral branches, in 1 species dichotomously branched.

simple, unbranched, upright, with eustelic vascular tissue.

bases dilated, clasping, forming sheath, open or fused, surrounding successive leaf primordia;

primordia glabrous or with long, uniseriate hairs.

to 6 pairs, ascending, usually approximate or overlapping except in shade forms, distance between 1st and 2d pinnae not or slightly more than between 2d and 3d pairs, basal pinna pair commonly much larger and more divided than adjacent pair, lobed to tip, basal pair oblong to oblong-lanceolate with lobed margins, remainder broadly spatulate with entire margins or 1 or more shallow lobes, apex rounded, venation pinnate.

exposed or embedded, 0.5–1.5 mm diam., thick-walled, with thousands of spores.

all 1 kind, trilete, thick-walled, surface rugate, tuberculate, baculate (with projecting rods usually higher than wide), sometimes joined in delicate network, mostly with ± warty surface.

not green, usually fleshy, round or linear, subterranean, mycorrhizal.

stalk 0–3(–10) mm, to 1/4 length of trophophore rachis;

blade ± gray-green, dull, oblong-linear to deltate, 1–2-pinnate, to 6 × 5 cm, firm.

blades compound to simple, rarely absent, veins anastomosing or free, pinnate, or arranged like ribs of fan.

1–3 pinnate, 2–3 times length of trophophore.

pinnately branched or simple.

absent or of widely scattered, long, uniseriate hairs, especially on petioles and rachises.

=180.