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.

0.8–1 mm, laterally winged toward apex.

0.6–1 mm, not winged.

with 8–15 distinct ribs, staying within fruit wall after ripening.

with 12–15 distinct ribs.

white, small, often decaying.

white, small, often decaying.

floating, 1 or 2–5 or more, coherent in groups, ovate, scarcely gibbous, flat, 1–8 mm, 1.3–2 times as long as wide, margins entire;

veins 3(–5) (if more than 3, outer ones branching from inner ones), greatest distance between lateral veins near or proximal to middle;

papillae not always distinct (one near apex usually larger);

lower surface very seldom slightly reddish (much less than on upper), coloring beginning from attachment point of root, upper surface occasionally diffusely reddish;

air spaces 0.3 mm or shorter; distinct turions absent.

floating, 1 or 2–few, coherent in groups, obovate, flat to thickish (but not gibbous), 0.8–4 mm, 1–2 times as long as wide, margins entire;

veins 1, sometimes indistinct, very rarely longer than extension of air spaces, not longer than 2/3 of distance between node and apex;

with or without small papillae along midline;

anthocyanin absent;

largest air spaces much shorter than 0.3 mm;

turions absent.

= 40, 42 (B), 50, 63, 126.

= 36 (U), 40 (U), 42 (G).