Extension: Cactus is a kind of plant growing in arid or semi-arid areas, belonging to Cactus. There are more than 65,438+000 genera and more than 2,000 species of cacti in the world. Most cactus plants are distributed in Central and South America, the United States and Africa. It has extremely rich forms, varieties and characteristics, and is an important plant in tropical and subtropical scenic spots, green belts, homes and courtyards.

Cactus mainly grows in high temperature and dry environment, and likes sunny, well-drained and warm and dry environment. Because they can live in the desert, they need little water and can absorb water from the air through their pores to maintain their growth. The basic shape of cactus is spindle-shaped or round sphere, which contains a lot of juicy tissues and can store water. The surface of cactus is covered with needle-like thorns or bristles to prevent herbivores.

As far as the species and quantity of cacti are concerned, they can be very small, with a height of no more than 3-4 inches, such as some succulents, or they can reach more than 50 feet, such as the largest species of cacti-palm cactus and giant cactus. In addition, many cactus plants can bloom, the size and color of flowers are different, and the flowering time is also different.

Cactus plays an important role in the ecosystem. Their roots are underdeveloped, but they use fleshy stems to absorb water and nutrients. Because cactus grows in harsh environment, it has strong water absorption and retention ability, which can prevent soil moisture from evaporating. At the same time, their bristles can also play a role in protection and ecological balance, such as preventing herbivores from destroying plants and reducing soil erosion.