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 generally larger than branch leaves, 1.3– 1.8 × 0.8–1 mm;

elliptic to lingulate-spatulate, widest above middle, hyaline cells nonseptate.

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

long-cylindrical, branch leaves terete to sometimes distinctly squarrose in shade forms.

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.

1–1.4 mm, ovate to ovate-lanceolate, gradually narrowed to an involute tip, hyaline cells somewhat bulging on concave surface and nearly plane on convex surface, with 4–8 large, elliptic, unringed pores per cell on convex surface and 1–4 irregularly rounded pores per cell on concave surface, internal commissural walls smooth to rather strongly papillose, chlorophyllous cells ovate-triangular with the widest part at or close to the convex surface.

dioicous.

dioicous.

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

proximal laesura less than 0.5 spore radius.

21–26 µm;

proximal and distal surfaces smooth, papillae indistinct;

proximal laesura 0.5–0.6 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 typically with 3 spreading (sometimes 2) and 2 pendent branches.;

branch stems with single layer of cortical cells.