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 lingulate to lingulate-triangular, 0.7–1.5 mm (to 3 mm in isophyllous forms), apex erose;

hyaline cells mostly 1–septate but in a few cells with 2–3 parallel septations, efibrillose to fibrillose throughout, pores present in hemiisophyllous and isophyllous forms.

weakly to strongly 5-ranked.

straight to somewhat curved, with spreading leaves.

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.

variable, broadly ovate to ovate-lanceolate, 1.3–5 mm; straight, hyaline cells on the convex surface with 4–8 µm round to elliptic pores in nearly continuous rows along the commissures, the concave surface aporose or with some porosity as on the convex surface.

dioicous.

unknown.

not seen.

18–33 µm, coarsely papillose on both surfaces;

proximal laesura less than 0.4 spore radius.

not seen.

fascicles with 2 spreading and 1–2 pendent branches.

fascicles with 2 spreading and 2 pendent in emergent forms, these reduced in aquatic forms to 2 per fascicle.