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.