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 triangular to triangular-lingulate, 1–1.3 mm, apex acute to slightly obtuse, border broad at base (more than 0.25 width);

hyaline cells narrowly rhomboid, mostly 0–1-septate and mostly efibrillose.

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

usually strongly 5-ranked.

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 to ovate-lanceolate, 1.1–1.5 mm, concave, straight, apex slightly involute;

hyaline cells on convex surface with numerous oval to elliptic pores along commissures grading from small pores near apex to large round pores at base, concave surface with large round pores in proximal portions of leaf.

dioicous.

monoicous or dioicous.

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

proximal laesura less than 0.5 spore radius.

19–27 µm, finely papillose on proximal surface, pusticulate on distal surface;

proximal laesura less than 0.4 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 mostly 3 spreading and 1–2 pendent branches.