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 narrowly lingulate-triangular, 1.2–1.8 mm, apex acute to apiculate, border not developed much along margins and narrow at base (occupying less than 0.25 the width of the base);

hyaline cells rhombic, mostly 0–1-septate.

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

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.

narrowly ovate-lanceolate, 1.2–1.5 mm, concave, straight, apex strongly involute, border entire, hyaline cells on convex surface with 3–9 faintly ringed rounded-elliptic pores along the commissures often quite small apically, largely aporose 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.

19–28 µm; coarsely papillose on both surfaces with a distinct ridged border around perimeter of proximal surface;

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.