Monarda fistulosa, bee balm 
This summer-blooming plant has pale pink to lavendar blooms popular with pollinators and gets to be about 4’ tall.
Penstemon digitalis, white beardtongue 
This spring-bloomer is 2-4’ tall and does well in full sun to part shade. It is a favorite of bumble bees, whose back-ends are frequently seen sticking out of the flowers.
This species may cross-pollinate with Penstemon smallii, which is typically a bit smaller with smaller leaves and pink flowers.
Sisyrinchium angustifolium, blue-eyed grass 
Not a grass at all, adorable little plant is in the iris family. Its leaves are reminiscent of grass but, like all irises, they are appressed at the base. This plant gets to be about 6" tall and brightens up the springtime with its delicate, pale blue flowers. It can handle light shade, but also thrives in full sun. It can handle a moist, well-drained soil but also tolerates drought well.
Oenothera fruticosa, sundrops or evening primrose 
This sunny, summer-flowering perennial loves poor, well-drained soil. This is a good plant with which to beautify a heavily "disturbed" area! When it's happy, it is prone to spreading. It stays between 1-2' tall.
Rudbeckia hirta, black-eyed susan 
This short-lived perennial with sunny summer flowers typically sets seed such that its presence will continue long-term in your garden. This species of Rudbeckia appreciates a moist soil, as long as it is well-drained. It typically gets to be 3-4' tall.