This is Argemone mexicana Mexican poppy, Mexican prickly poppy, flowering thistle, cardo or cardosanto. This plant is mainly used for its magnificent showy yellow flowers. This is a great plant if you are looking for something that can live in poor soil and stay alive with almost no water. The seed oil from this plant has been used as biodiesel. The oil can also be used to make soap, or as a fuel for lamps. When the seedpods are cut open they excrete a yellow latex. USDA Hardiness Zones 7 to 11