Flora of North America species comparison

leaves 0.7–1 mm (to 1.2 mm in hemiisophyllous forms) elongate-triangular to triangular-lingulate, apex obtuse-erose, to apiculate; usually fibrillose at least apically; in hemiisophyllous forms spreading and in anisophyllous forms appressed;

hyaline cells often septate at base.

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.

moderately long and tapering, unranked to weakly 5-ranked, leaves not much elongated at distal end.

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

1–1.7 mm, ovate-lanceolate, undulate and recurved when dry;

hyaline cells on convex surface with 3–10 round pores per cell in the cell angles and free, on concave surface with round wall thinnings in the ends and angles.

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.

unknown.

dioicous.

not seen.

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

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

branch stem cortex enlarged and with conspicuous retort cells.

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

branch stems green, cortex enlarged with conspicuous retort cells.