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, 1–1.7 mm, apex acute to slightly obtuse;

leaves usually appressed;

margins entire;

hyaline cells fibrillose and usually septate at base and sides.

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

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

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-lanceolate to lanceolate, 3–5.5 mm; straight but sometimes slightly falcate-secund; weakly undulate and recurved when dry;

margins entire;

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

dioicous.

dioicous.

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

proximal laesura less than 0.5 spore radius.

26–29 µm;

both surfaces distinctly papillose, appearing pusticulate to irregularly pusticulate;

proximal laesura mostly less than 0.5 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 2 pendent branches.;

branch stems green;

cortex enlarged with conspicuous retort cells.