Here just shows
Lyonia mariana. says it doesn't have fruit, but frons? or something like that...
http://aggie-horticulture.tamu...
I was thinking it looks much like my Farkleberry, Huckleberry, Sparkleberry,
Vaccinium arboreum, except you said the berries appear twice the size of blueberries and farkleberry has smaller berries.
http://aggie-horticulture.tamu...