Humans aren't the only species who invade and conquer. Plants are guilty, too. I was awestruck by acres of red-tipped green succulents flowering under a blue California sky next to a turquoise ocean. Then they were outed as a lethal beauty. An expert at the California Coastal Trail Association identified my fan photo as Carpobrotus edulis, or Ice Plant, and warned me by email that it "forms a large, thick mat that chokes out all other native plants and alters the soil composition of the environment." Even worse, as " a coastal invader, it competes with many endangered, threatened, and rare plants." Ice plant shows that colonialism is built into natural design, but the forward-thinking imperative is for us to weed it out.