Oxydendrum arboreum: the leaves are sour, hence the alternative name sorrel tree; a nice honey is made from the flowers, they say. A tree of the southeast, presumably making its way north. This one an arboretum specimen: you knew Green-Wood was also a ranked arboretum, didn’t you?
***
Yet another primer on how important masking is during this pandemic. Yes, the murdering ministers disagree, but then, they want to kill you. I mean, there’s no other explanation for their behavior, is there?
Backyard and Beyond 
I wondered what this was. Thanks.