Flora of North America species comparison

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

erect or ascending, sparsely pilose.

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.

pedicellate;

receptacle sparsely hispid;

sepals 5, spreading, 4-7 × 1-2 mm, strigose;

petals 5, 5-8 × 2-4 mm.

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.

discoid, 8-9 mm across;

achenes 5-8 per head, 4-6.4 × 2.8-4.4 mm, faces and margin covered with long spines, glabrous;

beak lance-subulate, straight, 1.6-3.8 mm.

roots absent.

and lower cauline leaf blades obovate to rhombic in outline, 3-parted or 3(-5)-foliolate, 1.8-5.2 × 1.6-4.2 cm, leaflets oblanceolate or divided into oblanceolate or linear segments, leaflet base narrowly acuminate, margins entire or distally dentate, apex rounded or acuminate.

= 32.