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 lingulate-spathulate to spatulate, widest at base and/or distal third, usually narrower in the mid region, 1–1.3 mm, apex narrowly to broadly truncate and ± fimbriate-lacerate, border narrow distally and expanded proximally to 0.25 width or more;

hyaline cells efibrillose, irregularly rhombic to subquadrate, many cells 2–4-septate.

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

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.

ovate-lanceolate, 1.1–1.4 mm, slightly concave, straight, apex involute;

hyaline cells on convex surface grading from aporose to few small round pores near apex to numerous semi-elliptic pores along commissures in middle and base of leaf, concave surface with a few large irregular to circular pores (1–4) occupying most of the cell width.

dioicous.

autoicous.

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

proximal laesura less than 0.5 spore radius.

20–27 µm, moderately granulate-papillose on both surfaces, distinct raise Y-mark sculpture on distal surface;

proximal laesura less than or equal to 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 3(4–5) spreading branches and 1–2 pendent branches.