Cacti Fact-i

What do you call more than one cactus? Cacti! That’s pronounced cact-eye. There are over 1,000 different kinds of cacti, each with their own unique characteristics. The six main cacti families are: cereus, cylindropuntia, echinocereus, ferocactus, mammillaria and opuntia. But you don’t have to be able to pronounce their names to have fun learning about them!

Cacti Families

Here are examples of particular kinds of cacti from each of the six families.

Cereus: Saguaro

Cereus: Saguaro

These cacti can grow very tall, up to 60′. And they live a long, long time, up to 200 years. If someone told you to think of a cactus, this is probably the one you’d picture in your head. They are green with “arms” (sometimes up to 25 of them!) and covered in sharp spines.

Cereus: Saguaro

Cereus: Saguaro

These cacti can grow very tall, up to 60′. And they live a long, long time, up to 200 years. If someone told you to think of a cactus, this is probably the one you’d picture in your head. They are green with “arms” (sometimes up to 25 of them!) and covered in sharp spines.

Cylindropuntia: Jumping Cholla

Cylindropuntia: Jumping Cholla

OK, these are kind of scary! They are shrub-like, sometimes tree-like cacti that produce long chains of hanging fruit. And on top of the chains? Very spiky little balls just looking for something (or someone) to stick to. While they can’t actually jump, the balls detach very easily and cling to clothing and skin with their painful fishhook-like barbs. That means a big ouch for people or animals, but easy access to new growing spots for the cactus.

Cylindropuntia: Jumping Cholla

Cylindropuntia: Jumping Cholla

OK, these are kind of scary! They are shrub-like, sometimes tree-like cacti that produce long chains of hanging fruit. And on top of the chains? Very spiky little balls just looking for something (or someone) to stick to. While they can’t actually jump, the balls detach very easily and cling to clothing and skin with their painful fishhook-like barbs. That means a big ouch for people or animals, but easy access to new growing spots for the cactus.

Echinocereus: Strawberry Hedgehog

Echinocereus: Strawberry Hedgehog

These lower-growing clumping cacti look a bit like a prickly hedgehog with their covering of sharp, white spines. Big 4″, purple flowers bloom after spring rains, from February to May.

Echinocereus: Strawberry Hedgehog

Echinocereus: Strawberry Hedgehog

These lower-growing clumping cacti look a bit like a prickly hedgehog with their covering of sharp, white spines. Big 4″, purple flowers bloom after spring rains, from February to May.

Ferocactus: Arizona Barrel Cactus

Ferocactus: Arizona Barrel Cactus

All the cacti in this family are round. They can be small and globe-like, or barrel-shaped and up to 10′ tall. From top to bottom, they’re fiercely armed with vicious spines. But they have a soft side, too. In late summer, their crowns bloom with a ring of colorful flowers.

Ferocactus: Arizona Barrel Cactus

Ferocactus: Arizona Barrel Cactus

All the cacti in this family are round. They can be small and globe-like, or barrel-shaped and up to 10′ tall. From top to bottom, they’re fiercely armed with vicious spines. But they have a soft side, too. In late summer, their crowns bloom with a ring of colorful flowers.

Mammillaria: Pincushion

Mammillaria: Pincushion

These little guys are perfect for growing in small pots, as most varieties don’t grow any taller than 6”. Sometimes they look fuzzy due to their overlapping spines and white “felt” on their skin. But don’t be tricked — they all have sharp spines! Pretty, bright-colored blooms appear in spring in a circle around their crowns.

Mammillaria: Pincushion

Mammillaria: Pincushion

These little guys are perfect for growing in small pots, as most varieties don’t grow any taller than 6”. Sometimes they look fuzzy due to their overlapping spines and white “felt” on their skin. But don’t be tricked — they all have sharp spines! Pretty, bright-colored blooms appear in spring in a circle around their crowns.

Opuntia: Prickly Pear

Opuntia: Prickly Pear

Sometimes these types of cacti are called “pancake” because their paddles are very flat and thin. Some species grow up to 7′ tall, while others stay close to the ground. They produce a bright red fruit called prickly pear, and the top paddles display bright blooms. You can actually eat a prickly pear paddle, which is called nopal in Spanish (pronounced no-pawl).

Opuntia: Prickly Pear

Opuntia: Prickly Pear

Sometimes these types of cacti are called “pancake” because their paddles are very flat and thin. Some species grow up to 7′ tall, while others stay close to the ground. They produce a bright red fruit called prickly pear, and the top paddles display bright blooms. You can actually eat a prickly pear paddle, which is called nopal in Spanish (pronounced no-pawl).

Did You Know?

  • Cacti live in the desert.
  • They survive with very little water.
  • When it rains, cacti collect a lot of water very quickly through their big network of shallow roots.
  • Deeper roots find water far underground.
  • Cacti turn water into a gel-like liquid stored in their interiors.
  • Thick skin and pointy spines protect their precious water supply from wild animals.
  • The oldest cactus ever known was a saguaro called Old Granddaddy. It lived over 300 years and was 40′ tall with 52 arms!

Looking for more kid-friendly activities to do at home? Check out our other Adventure Kids Camp activities!