Flora of North America species comparison

to 15 cm, tip mostly rounded;

sheath not winged.

shorter than 15 cm, tip mostly rounded;

sheath not winged.

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

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

0.5–0.7 mm, not winged.

0.5–0.6 mm, not winged.

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

with 30–60 indistinct ribs, staying within fruit wall after ripening.

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, 1 or 2–few, coherent in groups, obovate, scarcely gibbous, flat, 1–4 mm, 1–1.5 times as long as wide, margins entire;

veins 3, greatest distance between lateral veins near or distal to above middle;

papillae distinct on midline of upper surface (apical papilla scarcely larger than others);

lower surface often red (more intensely so than on upper), coloring beginning at attachment point of root, upper surface (especially near apex) sometimes with red spots;

air spaces to 0.3 mm;

turions sometimes present, rootless, olive to brown, 0.8–1.6 mm diam., sinking to bottom.

= 40, 42, 50.

= 40, 42 (G), 50, 80.