Basswood (Linden), Tilia americana
This pyramidal tree is messy. In addition to sap, it will drop leaves, fruits, bracts, and flower petals. I am putting a variety of photos here of bark, etc. to help identify the basswood (“bastwood” is its fascinating origin) as it provides a large early nectar flow.
For me, lindens bloom after catalpas, mid-June, and provide a major nectar flow. Super up upon budburst.