Flora of North America species comparison

not thickened basally, glabrous.

erect or ascending from caudices, not rooting nodally, distally glabrous or brown-pilose, not bulbous-based.

erect or ascending, often rooting at proximal nodes, glabrous or sparsely pilose.

reniform to broadly triangular in outline, 3-foliolate or deeply 3-parted, 1-4 × 1.6-4.4 cm, leaflets or segments 1-2x-parted, ultimate segments elliptic to oblanceolate or almost linear, margins entire or occasionally with 1-2 teeth, apex rounded to obtuse.

ovate to lanceolate or narrowly elliptic, 1.5-5.7 × 0.4-2.4 cm, base cordate to acute, margins finely denticulate or entire, apex broadly rounded to acuminate.

bracts linear to lanceolate or oblanceolate.

receptacle glabrous or brown-pilose;

sepals spreading, 7-12 × 4-9 mm, brown-pilose;

petals initially white, usually becoming red with age, 9-15 × 7-14(-18) mm.

receptacle glabrous;

sepals 4-5, spreading or reflexed from base, 2-3 × 1.5-3 mm, glabrous or pubescent;

petals 4-6, 2-6 × 1-2 mm;

nectary scales glabrous.

hemispheric to ovoid, 2-4 × 2-3 mm;

achenes 0.8-1 × 0.8 mm, glabrous;

beak deciduous, leaving stump 0.1-0.2 mm.

roots absent.

heads hemispheric, 5-8 × 7-16 mm;

fruit wall smooth, not veined, loose but not inflated, winged along suture, fruits winged achenes;

achenes 2.6-3 × 1.4-2 mm, glabrous;

beak persistent, lanceolate, 0.8-2.3 mm.