Flora of North America species comparison

green to red;

superficial cortical cells aporose Stem leaves lingulate-triangular, 1.2–1.6(–1.8) mm, apex ± involute;

border entire and broadened to about 0.25 the width of the base;

hyaline cells S-shaped, 0–1-septate, usually fibrillose in distal portion of leaf.

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.

not 5-ranked, terete.

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

ovate-lanceolate, 1–1.4 mm, imbricate to moderately spreading, concave, straight, strongly involute near apex;

hyaline cells on convex surface with elliptic pores along commissures, concave surface with large round pores away from commissures in proximal portions of leaf.

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.

dioicous.

dioicous.

20–28 µm; finely papillose on both surfaces, with distinct raised Y-shaped sculpture on distal surface;

proximal laesura 0.5 spore radius or more.

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

fascicles with 2 spreading and 1–2 pendent branches.

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

branch stems green, cortex enlarged with conspicuous retort cells.