Flora of North America species comparison

leaves triangular-ovate, more than 1.2 mm, usually appressed;

apex acute to apiculate, hyaline cells rarely septate or porose, apical region often fibrillose.

leaves 1.2–1.6 × 1 mm; rarely hemiisophyllous;

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

mostly unranked to weakly 5-ranked, often conspicuously falcate, leaves greatly elongated at distal end.

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

ovate-lanceolate to lanceolate, 1.6–5 mm, falcate toward branch tips, when dry often undulate and recurved, rarely weakly serrulate along the margins in submerged forms, leaves from middle of spreading branches with length to width ratio less than or equal to 1:0.28;

hyaline cells length to width ratio in apical convex surface region 8:1 or more, convex surface with 0–1 small round pores at apex, concave surface with faint round wall thinnings in cell apices and angles; chlorophyllous cells triangular to trapezoidal in transverse section, broadly exposed on the convex surface and exposed slightly on the concave surface.

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.

dioicous.

dioicous.

with scattered pseudostomata.

29–38 µm; covered with large papillae on both surfaces, appearing pusticulate;

proximal laesura less than 0.5 spore radius.

23–28 µm; coarsely granulate on both surfaces;

proximal laesura more than 0.50 spore radius.

fascicles with 2 spreading and 2–3 pendent branches.;

branch stems green, but often pinkish at the proximal ends, with cortex enlarged with conspicuous retort cells.

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.