A cactus (plural: cacti, cactuses or cactus) is a member of the plant family Cactaceae. Their distinctive appearance is a result of adaptations to conserve water in dry and/or hot environments. In most species, the stem has evolved to become photosynthetic and succulent, while the leaves have evolved into spines. Many species are used for ornamental plants, and some are also grown for fodder, forage, fruits, cochineal, and other uses. Cacti come in a wide range of shapes and sizes.