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 broadly ovate, 1.2–2.2 mm; straight;

apex rounded;

hyaline cells non-septate, convex surface with numerous small pores (less than or equal to 1/6 cell diameter) forming a continuous row along the commissures, concave surface aporose or with a few scattered pores along the commissures and cell ends.

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

short and blunt, sometimes lacking completely and plants simplex.

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.

broadly ovate, 1.4–2.5(–3) mm; straight;

apex rounded;

hyaline cells as in stem leaf.

dioicous.

dioicous.

exserted, with few pseudostomata.

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

proximal laesura less than 0.5 spore radius.

23–35 µm;

papillose on both surfaces, with indistinct Y-mark sculpture on distal surface;

proximal laesura 0.5 spore radius or less.

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 of 1–3 branches, 1–2 of these spreading, branches usually not numerous.