Cacti or cactuses are succulent plants, well known natives of desert areas in the Americas. They have also become naturalized to similar environments in other areas. An individual plant is called a cactus.
Like other succulents, cacti are well-adapted to life with little precipitation. Their leaves have evolved into needles, which in addition to allowing less water to evaporate than regular leaves, also defend the cactus against water-seeking animals. Their photosynthesis is carried out by their enlarged stems, which also store water. Unlike other succulents, the stem is the only part where this takes place.
Cacti come in many varieties in a wide range of shapes and sizes. Some grow to great heights. Some cactuses produce beautiful flowers, which like spines and branches arise from areoles. Many cactus species are nightblooming, as they are pollinated by nocturnal insects or small animals.
A number of cactus species are cultivated for use as houseplants, as well as for ornamental gardens. They often form part of xerophilic (dry) gardens in arid regions. Some cacti bear edible fruit.
A few examples of cacti: