A relative of Penstemon, but the showy spikes of flowers are in tighter heads and two-lipped, rather than the open-tubular Penstemon flowers. Through late summer in to autumn. Found in moist situations through the eastern half of North America, so preferring a moisture retentive soil in part shade. They will take more sun, but will need a better soil. Chelone in Greek means 'tortoise', which refers to the domed upper lip of the flower.... Although the common name is turtlehead!
The tubular flowers are classically insect-pollinated, and these are visited by a range of pollinators including honeybees, bumblebees and especially it seems solitary bees.