Black cohosh

A large, hairy, clump-forming North American native perennial of wet meadows, low woods, stream banks, and prairies. Its most distinctive feature is the perfoliate foliage - pairs of wrinkled, opposite, lance-shaped leaves whose bases fuse around the hairy stem, so the stem appears to pass through the leaf. From July to September, flat-topped clusters of small, fluffy white flowers feed a wide range of bees, butterflies, and other pollinators, while all parts of the plant are toxic and bitter.

A tall, clump-forming native legume of eastern North America grown for showy mid- to late-summer clusters of gold-yellow flowers accented by dark, curving anthers. The pinnately compound leaves carry a club-shaped gland on the petiole, and the long-lived plants reach 4-6 feet. Bumblebees work the pollen-only flowers, hummingbirds visit, and the seeds feed birds including bobwhites.

Arkansas blue star (Amsonia hubrichtii), also called threadleaf bluestar or Hubricht's bluestar, is a clump-forming native perennial from a tiny wild range in the Ouachita Mountains of Arkansas and Oklahoma that has become one of the most dependable foliage perennials in temperate gardens. It builds a soft, rounded, knee-to-waist-high mound of upright stems clothed in very fine, needle-like, thread-thin leaves, so the whole plant reads as a feathery green cloud through summer. In late spring the stem tips carry loose clusters of small, pale powder-blue, five-pointed star flowers, a quiet but pretty show that draws butterflies and other pollinators. Its headline act comes in autumn, when the fine foliage turns a clear golden-amber that lights up the border and earned it the Perennial Plant Association Plant of the Year for 2011. It wants full sun to part shade and is famously tough, adaptable, and deer-resistant, though it will flop open in too much shade or overly rich soil, so give it sun and a light shearing after bloom if you want it to stay upright.

A long-lived native perennial of central and eastern US woodland borders and prairie meadows with deep blue pea-shaped flowers in late spring, blue-green leguminous foliage, attractive black seed pods for winter interest, and a nitrogen-fixing root system (Fabaceae). Larval host for 6 documented butterfly species per NC State (orange sulphur, clouded sulphur, frosted elfin, eastern tailed-blue, hoary edge, wild indigo duskywing) - among the highest Lep-host-count perennials in the eastern flora.

A bold, moisture-loving native perennial of eastern North America that dies back to a woody base each winter and returns to throw up stout 2-6 ft stems topped with enormous 4-8 inch saucer-shaped flowers - white, pink, red, or burgundy, each with a contrasting central eye - from June into September. NC State Extension describes a herbaceous perennial hardy across USDA zones 4a-9b that thrives in wet to constantly moist soils, tolerates heat, humidity, and even brief flooding, and draws hummingbirds, butterflies, and other pollinators. The tropical-looking dinner-plate blooms make it a dramatic focal point for rain gardens, pond edges, and the back of a sunny border.

A large, vigorous, fountain-shaped deciduous shrub that earns its common name in late spring, when its arching stems are smothered in masses of pale-pink, yellow-throated, bell-shaped flowers. Native to China, it is one of the great old-fashioned spring shrubs - spectacular in full bloom, much loved by bees, and offering peeling brown bark for quiet winter interest. It is also genuinely big: expect 6 to 10 feet tall and wide at maturity, so give it room rather than fighting its size with the shears. The form to seek out is the Award-winning "Pink Cloud", which carries a clearer, richer pink than the variable seed-grown species.