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 triangular to triangular-lingulate, 1.2–1.7 mm, apex acute to sometimes shortly cuspidate due to involute margins near apex, border narrow at base (less than 0.25 width);

hyaline cells mostly efibrillose and aporose, 0–1(–2)-septate.

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

long and tapering, unranked.

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.

1.3–2.7 mm, ovate to ovate-lanceolate, 1.3–2.7 mm, concave, straight, apex involute;

hyaline cells on convex surface with 2–6 large, narrowly elliptic ringed pores along the commissures, but usually absent from marginal regions of leaf, concave surface aporose or with 1–4 large round pores per cell especially near base.

dioicous.

monoicous.

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

proximal laesura less than 0.5 spore radius.

22–32 µm, finely to irregularly coarsely-papillose on proximal surface, irregularly coarsely papillose on distal surface;

proximal laesura less than 0.5 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 with 2 spreading and 1–2 pendent branches.