Meadowsweet, Filipendula ulmaria, in the rose family, Rosaceae, is a lovely and conspicuous European wildflower, now naturalized in the eastern United States (known there as "queen-of-the-meadow").
The little blue flowers are always a delight to see. Its a harebell, Campanula rotundifolia (harebell family, Campanulaceae), seen in the Colorado Rocky Mountains.