Same here, until I looked at the size of the flower balls and then thought Viburnum maybe. Banners are fun when they keep you guessing, and beautiful as well.
I really like the way the blooms in your banner seem to follow a sinuous curve. It keeps my eye traveling back and forth.
There doesn't seem to be a page for this cultivar of Viburnum plicatum in the NGA plants database. Perhaps you'd consider proposing the addition. Does it have a nice fragrance?
Not sure how big these blooms are but reminds me of hydrangeas.
