This is another great wildlife tree--fragrant flowers produced in June are famous for the honey made be bees who relish their nectar.  Basswood trees are quite adaptable and especially suited to growing near streams.  They aren't so tolerant of pollution and get quite large, so they aren't often seen in urban conditions.  The name "basswood" is a corruption of bast, which refers to the tough inner bark found on this tree. Traditionally it was stripped off and used to make rope, baskets, etc.