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.

leaves equilateral triangular, 0.8–1.1 mm; often spreading;

apex more or less obtuse;

leaves often spreading;

hyaline cells usually septate and often fibrillose in proximal half of leaf.

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

unranked, ± straight, leaves moderately elongated 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-lanceolate, less than 2.2 mm, straight; undulate and sharply recurved when dry;

margins entire;

hyaline cells on convex surface with 0–1 apical pores and often with pseudopores, concave surface with to 12 round wall thinnings in cell angles and sometimes along commissures; chlorophyllous cells triangular in transverse section, just enclosed on the concave surface and broadly exposed on the convex surface.

dioicous.

unknown.

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

not seen.

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

branch stems green, cortex enlarged with conspicuous retort cells.

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

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