Flora of North America species comparison

nodal, never tuberous.

creeping or floating, rooting nodally, glabrous, not bulbous-based.

leafy, creeping or floating, not bulbous-based, without bulbils.

cauline, simple, petiolate;

blade undivided or 3-lobed, much longer than wide, margins entire.

linear to obovate, undivided or 3-lobed, 1.5-3.6 × 0.3-2 cm, lobes lanceolate or elliptic, margins entire, apex rounded to acuminate.

axillary, solitary flowers.

receptacle glabrous;

sepals spreading, 6-10 × 4-7 mm, glabrous;

petals 7-11, white or pink, 8-13 × 3-6 mm.

pedicellate (pedicels naked or leafy);

sepals deciduous soon after anthesis, 3;

petals 7-11, white or reddish;

nectary scale attached on 3 sides for at least half its length, forming pocket (sometimes mouth of pocket prolonged as short flap), glabrous, free margin entire;

style present.

achenes, 1-locular, 4.2-5.2 mm;

achene body oblong-lenticular, 1.3-1.7 times as wide as thick, prolonged beyond seed as corky distal appendage;

wall thick, smooth;

margin low corky band;

beak much shorter than achene body.

globose or hemispheric, 5-12 × 9-15 mm;

achenes 4.2-5.2 × 2.4-3.2 mm, glabrous;

beak persistent, lanceolate, straight or curved, 1-1.2 mm.

roots absent.

= 32.