Key Information
Cacti
| Species | About 1,750 species |
| Classification | Tracheophytes > Angiosperms > Eudicots > Cactaceae |
| Conservation Status | Varies, many Not Threatened |
| Habitat | Coasts to Mountains, Desert to Tropical |
Learning Point
- Cacti are an amazing family of plants, almost all of which are native to the Americas and have specialized adaptations that let them thrive in the harshest desert environments. The most striking features are their sharp spines, which are actually modified leaves that help protect the plant from being eaten and reduce water loss by limiting airflow around the plant’s surface. Cacti are also succulents, meaning they have thick, fleshy stems that expand and store enormous amounts of water.
Project
- Draw a picture of a cactus.
Location
| Locations | North and South America, parts of Africa |
Fun Facts
- A large Saguaro cactus can store enough water to last through a year or more of drought!
- Some cacti have soft, white, hairy coverings, like the “Old Man Cactus.” This fuzz helps protect the plant from the harsh sun and extreme heat, just like a hat!
- The giant Saguaro cactus is one of the slowest growing plants in the world. It might take up to 10 years just to grow its first inch!
- They are considered “New World” plants and were not found in Africa, Europe, or Asia until people brought them there.
- Many cactus flowers are large, beautiful, and sometimes only open at night. They rely on creatures like moths and bats to pollinate them while the sun is down.
Past Lessons
| 191 | November 19, 2025 | (North America) |