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 to spatulate, widest above middle (1.5 times as wide as the base), 1.5–2.5 mm, apex obtuse and dentate to lacerate;

border entire and little broadened at base, hyaline cells elongated-rhomboid, normally 1-septate, strongly fibrillose in distal portion, convex surface with numerous large pores and resorption gaps in apical angles, concave surface with large resorption gaps below and large resorption pores above.

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

unranked, terete.

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, 1.3–2.5 mm, straight, not concave;

apex weakly involute, broadly truncate with 6–10 conspicuous teeth;

border entire;

hyaline cells on convex surface with elliptic pores (4–8 per cell) along the commissures, concave surface with large round pores in distal half and proximal portion of cells.

dioicous.

dioicous.

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

proximal laesura less than 0.5 spore radius.

26–34 µm; finely granulose-roughened.

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.