Flora of North America species comparison

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

erect, glabrous, rooting at base, only very rarely rooting at proximal nodes.

basal and cauline, basal and proximal cauline leaf blades reniform to semicircular in outline, 3-lobed or -parted, 1-5 × 1.6-6.8 cm, base truncate to cordate, segments usually again lobed or parted, sometimes undivided, margins crenate or crenate-lobulate, apex rounded or occasionally obtuse.

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.

receptacle glabrous;

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

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

receptacle pubescent or glabrous;

sepals 3-5, reflexed from or near base, 2-5 × 1-3 mm, glabrous or sparsely hirsute;

petals 3-5, 2-5 × 1-3 mm;

nectary on petal surface, scale poorly developed and forming crescent-shaped or circular ridge surrounding but not covering nectary;

style absent.

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.

ellipsoid or cylindric heads, 5-13 × 3-7 mm;

achenes 1-1.2 × 0.8-1 mm, glabrous;

beak deltate, usually straight, 0.1 mm.

roots absent.

= 32.