Cactus

Cactus A member of a large family of plants typical of arid zones but found in a number of habitats; almost all are confined to the New World. In the Old World they are paralleled by various members of the spurge family (Euphorbiaceae). Cacti exhibit a wide variety of size, form, and adaptations to dry conditions, some very sophisticated. All species are succulents and store water, sometimes in the roots but usually in swollen, often barrel-like, stems. The plants are leathery with a thick waxy cuticle. The spines can be very intricate, ranging from simple prongs to parasols and long, soft hairs; they shade or insulate the cactus, protect it from animals, reflect light, and collect and absorb droplets of dew an important source of water. There is a wide range of flowers, often large and conspicuous. (Family: Cactaceae, c.2000 species.) >> cactus moth; spurge; succulent;