Flora of North America species comparison

leaves lingulate-triangular to lingulate, 1–1.4 mm, apex broadly rounded but becoming acute in hemiisophyllous forms, border strongly developed at base (more than 0.25 width);

hyaline cells rhombic and 0–3-septate with some cells in leaf midregion 2–septate.

leaves ovate-lingulate; 1–1.3 mm, apex broadly rounded;

hyaline cells nonseptate, aporose and fibrillose in at least distal half of leaf.

weakly to strongly 5-ranked.

2–3 spreading and 2 pendent leaves not much elongated at distal end.

ovate to ovate-lanceolate, 0.9–1.2 mm, concave, subsecund on some branches, apex involute;

hyaline cells on convex surface with numerous round to elliptic pores along the commissures, grading from small round pores near apex to round pores near base, on concave surface with large round pores in proximal portions of leaf.

ovate, 1–1.5 mm; straight;

not or weakly undulate or recurved when dry;

margins entire;

hyaline cells short and wide, convex surface with 1–3 small pores per cell and on concave surface with large round wall thinnings in the cell angles; chlorophyllous cells equilateral-triangular in transverse section, broadly exposed on convex surface and just reaching to well-enclosed on concave surface.

dioicous.

monoicous.

18–33 µm, coarsely papillose on both surfaces;

proximal laesura less than 0.4 spore radius.

27–42 µm;

both surfaces smooth, proximal surface with distinct bifurcated Y-mark sculpture surrounded by distinct circular border, distal surface with distinct raised border around margins;

proximal laesura usually less than 0.4 spore radius.

fascicles with 2 spreading and 1–2 pendent branches.

stems green;

cortex enlarged, with conspicuously long-necked retort cells.