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 to lingulate, 1.1–1.4 mm, apex broad-rounded to narrowly truncate, border very broad at base (more than 0.3 width);

hyaline cells efibrillose, rhombic, mostly 1-septate but can be non-septate.

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

long and tapering, 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-lanceolate, 0.9–1.4 mm, concave, straight, apex involute;

hyaline cells on convex surface with very small ringed pores (less than 0.25 cell width) along commissures near apex, changing abruptly to large elliptical pores (0.4 cell width or more) basally, concave surface with large round pores in proximal margins and leaf base.

dioicous.

dioicous.

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

proximal laesura less than 0.5 spore radius.

17–26 µm, finely papillose on both surfaces;

proximal laesura 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 1–2 pendent branches.