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, 1.2–1.6 mm, broadly apex acute to narrowly truncate and toothed, border narrow or indistinct at base (less than 0.25 the width);

hyaline cells rhomboid, mostly 0–1-septate;

convex surface with membrane pleats, concave surface with 1–3 rounded membrane gaps occupying most of cell.

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

somewhat 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, 1.3–2 mm, strongly concave, apex strongly involute;

margins entire to somewhat toothed near apex, hyaline cells on convex surface with numerous ringed elliptic pores (6–10) along commissures, concave surface mostly aporose except near margins;

Sexual condition dioicous or monoicous.

dioicous.

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

proximal laesura less than 0.5 spore radius.

21–23 µm; minutely papillose.

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.