Vinca major (Greater Periwinkle)

Native from southern Europe to the Caucasus, this trailing evergreen perennial belongs to the dogbane family. Long stems root where their nodes touch soil, forming dense mats. Opposite, oval leaves have finely hairy edges; cultivated forms may have cream margins. Blue-violet flowers have five lobes arranged like a pinwheel. Broken stems carried by water can establish new colonies. It is invasive in California and several southeastern states in the USA, where it crowds out native plants. The plant is poisonous if eaten. Photographed in Bogotá, Colombia.