You have identified:

Bouncing Bet
(Saponaria officinalis)

© USDA, NRCS
http://plants.usda.gov

General Information: Also known as soapwort, bouncing bet is primarily found along roadsides and waste places.  A member of the Pink family, it generally blooms in summer and early fall. The stem is smooth and stout, 1’ to 2’ high. Leaves are oval and have 3 to 5 prominent ribs.  Flowers are pink or white, approximately 1” wide, fragrant, and are often in dense clusters with indented petals at the tip.

Gleason, H. A.  1952.  The New Britton and Brown Illustrated Flora of the Northeastern United States and Adjacent Canada.  3 vols.  New York: Hafner Press.

Newcomb, L.  1977.  Newcomb's Wildflower Guide.  Boston: Little, Brown, and Company.