Flora of North America species comparison

leaves ovate-triangular to triangular, 1–1.6 mm; appressed to spreading;

apex acute to slightly obtuse;

hyaline cells often fibrillose and often 1-septate.

leaves triangular-ovate, more than 1.2 mm, usually appressed;

apex acute to apiculate, hyaline cells rarely septate or porose, apical region often fibrillose.

straight and unranked, in capitulum tapering at distal end to a point, leaves greatly elongated at distal end.

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

ovate-lanceolate to lanceolate, 2–3.5 mm; straight, undulate and slightly recurved when dry;

margin serrulate;

hyaline cells on convex surface with 0–1 small pores at cell apex on concave surface with round wall thinnings in cell angles (often indistinct or lacking); chlorophyllous cells trapezoidal in transverse section and exposed more broadly on the convex surface.

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.

monoicous.

dioicous.

26–40 µm; ± roughly to densely granulose.

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

proximal laesura less than 0.5 spore radius.

stems green, cortex enlarged with conspicuous retort cells.

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.