Flora of North America species comparison

leaves long triangular-ovate, 1–2 mm; usually appressed;

apex acute to apiculate, hyaline cells only rarely septate or aporose but often fibrillose in apical region.

pale green;

superficial cortex of 1–2 layers of thin-walled and well differentiated cells.;

stem leaves large, ovate to oblong-ovate, ca. 2 mm, more or less spreading;

apex rounded and serrulate;

hyaline cells fibrillose and often 1–septate, convex surface generally aporose, concave surface with 1–several round pores per cell in ends and angles.

unranked, straight to slightly curved, leaves somewhat elongated at distal end.

unranked to slightly 5-ranked, often short and blunt at distal end.

1.5–2.7 mm, ovate-lanceolate to lanceolate; straight to falcate toward branch tips; when dry often undulate and lightly recurved, margins entire to rarely weakly toothed along the margins in flaccid aquatic forms, hyaline cells on convex surface with 0–1 small round pores at apex, on 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 to broadly on the concave surface.

ovate to oblong-quadrate, 1.2–2.5 mm, not undulate or recurved when dry, strongly toothed across apex and serrulate on margins;

hyaline cells with to 4 small round ringed pores at cell ends on convex surface, small round wall thinnings in the cell ends and angles on the concave surface; chlorophyllous cells trapezoidal in transverse section, more broadly exposed on the convex surface.

dioicous.

monoicous.

30–43 µm; the superficial surface coarsely papillose to papillose reticulate.

38–48 µm;

both surfaces covered with fine to moderately coarse papillae;

proximal laesura less than 0.4 spore radius.

fascicles with 2 spreading and 2–3 pendent branches.;

branch stems green, cortex enlarged with conspicuous retort cells.

fascicles with 1–2 spreading and 0–1 pendent branches.;

branch stems green, with cortex enlarged with conspicuous retort cells.