Flora of North America species comparison

to 20 per plant, blackish, usually extremely narrow, often almost hairlike, less than 0.1 mm diam., proliferations not reported.

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

spheric, 3-12 mm diam., succulent, cormlike with perforation at apex, apical meristem located at bottom of cavity through which leaves emerge at top, leaves 2 per stem.

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.

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 to 0.6cm, 0.1-0.2 times as long as trophophore blade.;

trophophore blade lying nearly flat on ground, not folded longitudinally, pale green throughout, deltate to cordate, to 3 × 2 cm, contracted abruptly at truncate to cordate base, apex with apiculum.

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

coarsely reticulate with included veinlets.

arising at ground level, 1-5 times as long as trophophore;

sporangial clusters usually short, less than 1 cm, 2-3 mm wide, with 3-8 pairs of sporangia, apiculum to 1.5 mm.

pinnately branched or simple.

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