Cutleaf coneflower gets tall, anywhere from 2 to 9 feet depending on conditions, with yellow petals that hang back from a green center cone. Rudbeckia laciniata is a native perennial spreading 18 to 36 inches wide in full sun, hardy from Zone 3 through Zone 9.
Bloom comes in late summer and runs into fall, held well above the foliage on branching stems. The deeply lobed leaves are the source of the name and give the plant a coarse texture through the season.
Height is the thing to plan for. In moist rich ground this reaches the top of its range and needs a back-of-border position or something behind it to lean on. In leaner, drier soil it stays shorter.
It grows wild in wet meadows, along streams, and in moist woodland edges, so it takes wet ground and part shade better than most rudbeckias. It spreads by rhizome into a colony over time. Bees and butterflies come to the flowers, and goldfinches take the seed through winter.