Hydrangea

Smooth hydrangea, also called sevenbark, is a small to medium multi-stemmed deciduous shrub growing to about 2 m, native to the eastern United States. Wikipedia says the name sevenbark comes from the stem bark, which peels in several thin layers of different colours, and that the plant spreads by stolons to form colonies. Cunningham lists it under the folk name Seven Barks and gives it one use, hex-breaking: the bark is carried, scattered around the home or burned to remove a hex. The AHPA botanical safety handbook covers the root and gives sevenbark and wild hydrangea as other common names. It notes cyanogenic glycosides (hydrangin), and says the flower and leaf have been reported to cause toxic symptoms in humans, assumed to be due to hydrangin, which is also reported in the root. It also records allergic contact dermatitis, mainly in agricultural workers, and dizziness and chest oppression after an overdose.