Close-up of a Southwest Ocotillo Bloom. The ocotillo is one of the oddest and most conspicuous Arizona plants, it was named after Pierra Fouquier, a French professor of medicine. During drought it sheds its leaves to conserve moisture. Red flowers are 1/2 to 1 inch in length, with five short lobes curled back into 10-inch clusters. They appear at the ends of branches March through June or later, depending on rainfall.