Flora of North America species comparison

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

erect, 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.

reniform to semicircular, undivided or shallowly 3-lobed, 2.5-5 × 3-7 cm, base truncate to nearly cordate, margins crenate or dentate, apex rounded or obtuse.

receptacle glabrous;

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

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

pedicellate;

receptacle hispid;

sepals 5, reflexed 1 mm from base, 3-5 × 1-2 mm, hispid;

petals 5, 4-5 × 2-3.5 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.

hemispheric to globose, 4 × 6 mm;

achenes 15-20 per head, 2.5-3 × 2-2.5 mm, faces covered with high sharp tubercles or low spines, glabrous, margin smooth;

beak deltate, straight, 0.8-1 mm.

roots absent.

= 32.