This section is from the book "Who's Who Among The Wild Flowers", by W. I. Beecroft. Also available from Amazon: A Field Guide to Edible Wild Plants.
Spiraea tomentosa. Rose Family. July - Sept.
A shrubby plant, with erect, woolly stems 2 - 4 feet high, found in low ground or on hillsides. New Brunswick to Georgia, west to Minnesota and Kansas.
Pink or magenta, rarely white, in dense, steeple-like clusters.
Dark green above, whitish-woolly beneath, toothed.

Hardhack.
 
Continue to: