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 elongate-triangular, 1.3–1.5 mm; often spreading;

apex obtuse;

hyaline cells mostly efibrillose and 1–septate in proximal half and lateral portions of leaves.

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

unranked, often blunt and with 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 to broadly ovate at branch base and becoming ovate-lanceolate at branch tip; 1.2–1.5 mm; undulate when dry, margins serrulate;

hyaline cells of convex surface with 0–5 pores or pseudopores at cell apex, concave surface with faint round wall thinnings in cell angles, but may be absent, chlorophyllous cells trapezoidal in transverse section, exposed more broadly on convex surface.

dioicous.

probably dioicous.

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

proximal laesura less than 0.5 spore radius.

not seen.

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 2–3 spreading and 0–2 pendent branches.;

branch stems green, with cortex enlarged with conspicuous retort cells.