Dangleberry aka Blue Huckleberry (Gaylussacia frondosa)

2015-5-8 www9 Patuxent Research Refuge, Anne Arundel County, MD
https://gobotany.newenglandwild.org/species/gaylussacia/frondosa/
see also:
http://www.florafinder.com/Species/Vaccinium.php

Deerberry (Vaccinium stamineum) looks a lot like lowbush blueberry but the edges of the flowers (the bell)
don't flare out like the blueberries do, so watch for that when looking at blueberries.