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 short-rectangular, 0.8–1.1 mm, hyaline cells mostly non-septate and absent comb-fibrils.

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

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 to ovate-elliptic, 1.4–1.8 mm;

hyaline cells on convex surface with numerous pores along the commissures;

comb-lamellae obvious only in proximal 1/2 of leaf; chlorophyllous cells broadly triangular in transverse section and well-enclosed on the convex surface.

dioicous.

dioecious.

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

proximal laesura less than 0.5 spore radius.

(22) 24–27(–28) µm, surface granulate.

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 hanging branches.;

branch stems with hyaline cells non-ornamented, no or weak funnel-like projections on the end walls of cortical cells, cortical cell walls usually with large round pores.