Flora of North America species comparison

leaves triangular, large, less than 1.7 mm, mostly appressed to stem, apex weakly apiculate to narrowly obtuse;

hyaline cells efibrillose and seldom to often septate at base and sides.

leaves very small, less than 0.8 mm, triangular with blunt rounded apex.

unranked, long and tapering, leaves greatly elongate at distal end.

erect in distal portion of plants.

ovate-lanceolate to lanceolate in aquatic forms, ovate to ovate-lanceolate in emergent forms, greater than 2.5 mm, often falcate-secund, especially in submerged forms, weakly undulate and recurved when dry;

margin entire, hyaline cells on convex surface with 0–1 pores per cell, concave surface with round wall thinnings in the cell apices and angles; chlorophyllous cells narrowly triangular in transverse section and well-enclosed on the concave surface.

large, 2.8 mm or longer, sub-squarrose, ovate, involute to broad, truncate apex with more than 6 teeth;

hyaline cells with up to 6 non-ringed pores on convex surface with few or no pseudopores, 2–4 elliptic ringed pores on concave surface in corners or along commissures, internal commissural walls minutely papillose (best viewed in oblique sections), rarely smooth; chlorophyllous cells narrowly triangular in transverse section, more broadly exposed on convex surface, enclosed on concave surface.

dioicous.

monoicous.

with abundant pseudostomata on surface of capsule.

31–43 µm; coarsely papillose on both proximal and distal surfaces, raised Y-mark sculpture on distal surface;

proximal laesura moderately long, 0.4–0.7 spore radius.

fascicles with 2 spreading and 2 pendent branches.;

branch stem green, cortex enlarged with conspicuous retort cells.

fascicles with 2 short-spreading and 3 long-tapering pendent branches.

not seen.