Cacti Generic

The family Cactaceae comprises many species of flowering plants with succulent (water-storing) stems. The presence of a structure called the areole sets cacti apart from all other plants. Areoles give rise to flowers, new branches, and spines. There are many different types of spines—some are soft and feathery to protect the plant from intense sunlight, while others are tough and sharp for protection. Cacti may be one of the few sources of water in arid regions, so spines prevent animals from accessing their supply of water. To prevent water loss, cacti are covered with a waxy substance called a cuticle. Another way they conserve water is by opening structures called stomata at night, rather than during the day like most plants. Stomata are microscopic pores on the plant through which carbon dioxide enters for photosynthesis.
Cacti vary in size based on their species. Perhaps the smallest cacti species is Blossfeldia liliputana, a South American plant that’s less than an inch (2.5 centimeters) in diameter when fully grown. The tallest cactus, the Mexican giant cardon, reaches over 60 feet (18 meters).

Basic Information

Ecology and Habitats

Deserts.

Dietary Needs and Habits

The root systems of most cacti spread out close to the surface to absorb as much rainwater as possible. Some species are so good at storing water that they can live in drought conditions for several years.

Biological Cycle

Cacti are flowering plants that produce seeds. They are able to bloom every year, but they will produce an abundance of flowers in response to heavy rains. Flowers differ in appearance and scent to attract specific pollinators, such as insects and bats. Cacti are slow growers and can live for many years. For example, saguaro cacti can live up to 175 years. They do not grow their first arms until they are between 75 and 100 years old.