Flora of North America species comparison

leaves 1.2–1.6 × 1 mm; rarely hemiisophyllous;

hyaline cells nonseptate or more typically mostly septate, comb-lamellae present on interior wall.

leaves triangular, large, less than 1.7 mm, mostly appressed to stem, apex weakly apiculate to narrowly obtuse;

hyaline cells efibrillose and seldom to often septate at base and sides.

clavate, tapering to short point, tightly imbricate at proximal end to somewhat spreading at distal end in less compact forms.

unranked, long and tapering, leaves greatly elongate at distal end.

ovate-elliptical to elliptical, 1.5–2.1 × 0.8–1.4 mm;

hyaline cells on convex surface with numerous moderate-sized round pores along the commissures, comb-lamellae present throughout most of leaf; chlorophyllous cells broadly triangular in transverse section and well-enclosed on the convex surface, end wall not thickened.

ovate-lanceolate to lanceolate in aquatic forms, ovate to ovate-lanceolate in emergent forms, greater than 2.5 mm, often falcate-secund, especially in submerged forms, weakly undulate and recurved when dry;

margin entire, hyaline cells on convex surface with 0–1 pores per cell, concave surface with round wall thinnings in the cell apices and angles; chlorophyllous cells narrowly triangular in transverse section and well-enclosed on the concave surface.

dioicous.

dioicous.

with scattered pseudostomata.

23–28 µm; coarsely granulate on both surfaces;

proximal laesura more than 0.50 spore radius.

fascicles with 2 spreading and 1 pendent branch.;

branch stems with cortical cell comb-lamellae visible on interior wall, conspicuous funnel-like projection on interior end walls extending to next cell less than one half its length, pores in superficial wall restricted to leaf bases.

fascicles with 2 spreading and 2 pendent branches.;

branch stem green, cortex enlarged with conspicuous retort cells.

not seen.