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-lingulate to lingulate; 0.8–1.2 mm;

apex rounded and sometimes erose;

hyaline cells non-septate or sometimes septate, usually fibrillose in distal 1/2 of leaf, convex surface with very small pores (ca. 2 µm) along commisures and free, concave surface with fewer commissural pores.

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

turgid and often strongly curved.

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-lanceolate; 1.4 or more mm; mostly subsecund;

hyaline cells on convex surface with numerous small (2 µm or more) pores along the commissures and sometimes free, concave surface with no pores or fewer small pores along the commissures.

dioicous.

not known.

not seen.

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

proximal laesura less than 0.5 spore radius.

not seen.

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 2 pendent branches.