golden ragwort
Packera aurea

Hardiness: Zones 3 to 8
Plant type: Herbaceous perennial
Height: 6"-  2.5'
Spread: 6"-1.5'
Sun: Part to full shade                                                                                                          Water: Medium to wet                                                                                                                Bloom time: April to June
Bloom color: Yellow
Soil: Moist, organically rich soils, Acid (<7pH).

Notes: Tolerates seasonal flooding, good for rain gardens

More information on this plant here.