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 lingulate-triangular to triangular-lingulate, equal to or less than 1.2 mm, more or less spreading;

apex obtuse;

hyaline cells mostly fibrillose and nonseptate.

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

straight to distinctly curved, leaves becoming substantially longer at distal end of the branch.

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, 1.5–2 mm, straight to slightly subsecund, only slightly undulate and recurved if at all;

margin entire;

hyaline cells on convex surface with numerous small free pores, on concave surface with numerous round free pores, cells relatively short in basal region (similar to mid region); chlorophyllous cells ± triangular in transverse section, just reaching concave surface or slightly enclosed.

dioicous.

dioicous.

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

proximal laesura less than 0.5 spore radius.

25–32 µm, finely papillose on both surfaces.

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, with cortex enlarged with conspicuous retort cells.