Weld produces one of the oldest dyes, a rich yellow. Combined with woad (Isatis tinctoria) it also produces an excellent green. Weld was used from ancient times until the late 1800s. Synthetic dyes then became cheaper and easier to process. Weld still hangs around wild in CA, CO, CT, DE, IA, IL, IN, MA, MD, MO, NJ, NY, OH, OR, PA, RI, WA, BC, and NS. Beal Gardens, MSU, 6/11/15. Mignonette family, Resedaceae.