Tree-growth responses to flood damage can be used to document the frequency and magnitude of paleofloods, thereby extending the historical period of record and improving estimates of flood recurrence. Common responses include the formation of scars, sprouting from tilted stems, and eccentric ring growth; occasionally, ring-anatomical changes develop following damage to leaves and buds, or to prolonged root flooding that does not injure trees. The annual formation of rings permits flood dating to within a year, and sometimes to within several weeks in the case of anatomical responses. The average maximum height of scars provides a reliable indicator of paleoflood stages along both low- and high-gradient streams. Magnitude also can be estimated by recovering information of any kind from trees at successively higher flood-plain elevations. This paper discusses numerous paleoflood studies based on botanical evidence, and considers practical applications that include detection, sampling, and interpretation of botanical information.