Flora of North America species comparison

to 15 cm, tip mostly rounded;

sheath not winged.

to 1.5 cm, tip rounded to pointed;

sheath not winged.

ovaries 1-ovulate, utricular scale with narrow opening at apex.

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

0.5–0.7 mm, not winged.

1–1.35 mm, not winged.

with 10–16 distinct ribs, staying within fruit wall after ripening.

with 15–29 distinct ribs.

white, small, often decaying.

white, small, often decaying.

floating, 1 or 2–5 or more, coherent in groups, obovate, flat or gibbous, 1–3.5 mm, 1–1.5 times as long as wide, margins entire;

veins 3, greatest distance between lateral veins near middle;

very distinct papillae near apex, some smaller indistinct ones on midline of upper surface;

lower surface very often red colored (more intensely than on upper), coloring beginning at attachment point of root, lower upper surface sometimes with red spots;

air spaces 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.

= 40, 42.