Flora of North America species comparison

to 3 cm;

tip usually sharp pointed;

sheath winged at base (wing 1–2.5 times as long as wide).

to 1.5 cm, tip rounded to pointed;

sheath not winged.

ovaries 1-ovulate, utricular scale open on 1 side.

ovaries 1-ovulate, utricular scale open on 1 side.

0.5–0.8 mm, not winged.

1–1.35 mm, not winged.

with 8–26 distinct ribs, falling out of fruit wall after ripening.

with 15–29 distinct ribs.

small, white, often decaying.

white, small, often decaying.

floating, 1 or 2–few, coherent in groups, ovate-lanceolate, flat, 1–6 mm, 1–3 times as long as wide, margins entire;

veins 3, greatest distance between lateral veins near or proximal to middle; 1 often very distinct papilla near apex on upper surface and 1 above node;

anthocyanin absent, no reddish color;

largest air spaces much shorter than 0.3 mm; distinct turions absent.

floating or (rarely) submersed, 1 or 2–few, coherent in groups, ovate to lanceolate, flat, thin, 1–5 mm, 1.3–3 times as long as wide, margins entire;

veins 1, mostly prominent, longer than extension of air spaces, or running through at least 3/4 of distance between node and apex;

with or without small papillae along midline of upper surface;

anthocyanin absent;

largest air spaces much shorter than 0.3 mm;

turions absent.

= 40, 42, 50, 60, 80, 84.

= 40, 42.