Greater? After lesser yesterday, do we need another celandine? Both are invasive. But greater flowers are only about half the size of yesterday's one-inch blooms. These plants are larger, about two feet verses six inches. They are unrelated, this in the poppy family, lesser a buttercup. Both are poisonous, so of course they became herbal medicines. Greater grows in partial to full shade in CT, DE, GA, IA, IL, IN, KY, MA, MD, ME, MI, MN, MO, MT, NC, NH, NJ, NY, OH, PA, RI, TN, UT, VA, VT, WA, WI, WV, BC, MB, NB, NS, ON, PE, and QC. Lenawee Co MI, 5/16/11.