Gromwell is a traditional plant of herb gardens. It has been used as a contraceptive, depurative, diuretic, lithontripic, oxytoxic and sedative. Glad to say I didn't know what a lithontripic does. Whether or not it is effective, gromwell seems relatively safe.
You can get 4 ounces of seed, which is the most used part, for $ 10.68 on eBay. Gromwell has escaped in CT, IL, IN, MA, ME, MI, MN, NH, NJ, NY, OH, PA, RI, TN, VT, WI, MB, NB, ON, and QC. Beal Garden, MSU, 5/3/12. Borage family, Boraginaceae.