If you look closely at the flat-topped flower clusters of the native Wild Hydrangea (pictured above), you'll see small, rather insignificant flowers on the inside and beautiful large, white flowers circling the perimeter.
 
     Those larger flowers are infertile; their purpose is to serve as a flag waving pollinators over so they can slurp the nectar from the small, fertile flowers on the inside.  
 
     These fertile flowers do not exist with the majority of non-native hydrangeas and popular hydrangea cultivars; instead, all you get are a full clump of showy, infertile flowers.   These bushes offer no value for pollinators, and the flower heads can get so heavy they droop to the ground for support.
 
     Native hydrangea, on the other hand, flowers reliably from May through August and attracts bumble and other native bees, butterflies, beetles, wasps and a host of other flying things.  It's also one of the few larval hosts to the Hydrangea sphinx, and its seeds are an important food source for songbirds.
 
     Fun fact: The Cherokees used this plant variously as an antiseptic, a stimulant, for stomach problems and to treat burns and sore muscles. (North Carolina Extension Gardener Plant Toolbox)