Cactus is a term applied to any plant from the family Cactaceae, there are around 141 genera in this family and approximately 2,000 species, with many more cultivars and hybrids. The plural is cacti or cactuses, meaning multiple plants. A cactus is a succulent perennial plant that doesn't produce typical leaves, they may be completely absent, reduced or modified into scale or spine structures to lessen water loss. Cacti retain and store water in their stems, which are green and photosynthetic. These are evolutionary adaptations allowing plants to survive in dry, arid environments with irregular rain or little water available. Cacti are used in a mutlitude of ways, they are widely grown as ornamental plants, some are used medicinally and some are cultivated commercially for food. They are relatively simple to grow, requiring bright light and infrequent watering - perfect for the forgetful gardener! Cacti may be herbaceous perennials or woody plants, they vary greatly in their size and appearance. Cacti can be distinguished from succulents by their areole structures. Areoles are areas from which spines, bristly hairs, flowers or stems develop from, they may be raised or depressed and they are often coloured differently to the rest of the plant. Most cacti are terrestrial, meaning they grow in the ground, however there are also epiphytic cacti species, which grow on the surfaces of other organisms and glean nutrition from their immediate surroundings. They range in their habits and hardiness ratings, most are tender and won’t cope with freezing temperatures, but there are also some species which can! Some do better in full, direct sunshine and the epiphytic species tend to prefer bright, indirect light in partially shaded conditions. All grow best in well-draining soil. You can find out more in-depth care information for many species and cultivars on their individual plant profiles. The term ‘succulent’ includes cactus plants, as all cacti store water and are therefore succulent. However, not all succulents are cacti! Cactus plants store water only in the stems and succulents, by contrast, are usually all about the leaves!