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-lingulate, 0.8–1.4 mm, spreading to appressed;

apex acute to narrowly obtuse, hyaline cells nonseptate and fibrillose near apex.

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

unranked or weakly 5-ranked, straight to strongly curved, leaves moderately 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 narrowly ovate-lanceolate, 1.8–3.4 mm; straight to strongly subsecund; weakly undulate and recurved when dry;

margins entire;

hyaline cells on convex surface with 1–2 free pores per fibril interval, concave surface aporose or rarely with a few wall thinnings in cell ends and angles; chlorophyllous cells trapezoidal in transverse section and narrowly exposed on concave surface.

dioicous.

dioicous.

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

proximal laesura less than 0.5 spore radius.

33–40 µm.

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 1–2 pendent branches.;

branch stems green but sometimes reddish at proximal end, with cortex enlarged with conspicuous retort cells.