Count the ways a flower can be white in early summer:
A white version of obedient plant in a frontyard raingarden fed by water from the roof,
The first summer bloom of rose mallow hibiscus in a backyard swale fed by water from the uphill neighbors,
boneset getting ready to pop,
some elderberry flowers late to the party, growing next to the chicken coop,
black cohosh up among the boulders on the Princeton ridge,
oakleaved hydrangia, both growing in front of the Whole Earth Center,
Yucca filamentosa in a neighbor's front yard,
and, at Westminster's parking lot raingardens, some unintended white clover,
and Queen Anne's lace.
These last three on nonnative; the rest are native to the eastern U.S.