Barrel Cactus vs Saguaro Cactus: What's the Difference?

Barrel Cactus vs Saguaro Cactus: What’s the Difference?

by | Oct 26, 2018

To those of us new to the desert, it can be hard to tell the difference between a barrel cactus vs saguaro cactus. These large cacti grow across the southwestern United States. Young saguaros can closely resemble barrel cacti, adding to the confusion.

Let’s break down the differences between these two cacti groups.

But first, let’s get one thing straight. The term “barrel cactus” doesn’t actually describe a single species of cactus. In fact, barrel cacti can be any roundish, barrel-shaped cacti from the genus Ferocactus or Echinocactus. Collectively, these two genera include roughly 40 different species of barrel cactus. No wonder things get confusing!

Of course, you can always use PlantSnap to help tell the difference between some tricky plants.


barrel cactus


Barrel Cactus vs Saguaro Cactus: Tactics for Telling them Apart

Luckily, there are a lot of relatively easy ways to tell the difference between a saguaro cactus and a barrel cactus. Let’s go through them.


1. Size and Shape

The most obvious difference between a saguaro cactus and a barrel cactus is size and height. Saguaros grow up to 50 feet in height, though it can take them 200 years to reach that height. A barrel cactus will only top out around five to ten feet high. So if the cactus you’re looking at is tree-height, it’s probably a saguaro.

Of course, some other cacti species grow taller than your hip, such as prickly pear. But they’re not as fat or rounded as saguaro cati or barrel cacti.

Even at equal height, it should be relatively easy to tell which species of cactus you’re looking at.

A saguaro generally has some branches, whereas a barrel cactus will never have branches. They may grow in clumps of rounded cacti, but won’t have branches.

Finally, a saguaro will be narrower in relation to its height. Barrel cacti are very thick and stout in relation to their height. Keep this in mind when looking at young saguaro – they’ll be skinnier, rather than rounded!


young saguaro


2. Location

Saguaro cacti grow in the Sonoran Desert of North America, ranging from northwestern Mexico to the western half of Arizona (and a bit of California or Baja California). If you’re outside of this range, it’s probably not a saguaro.

Meanwhile, barrel cacti can be found across much of the southwestern US, overlapping with the saguaro’s range.


3. Fruits

The fruits of both saguaro cacti and barrel cacti are edible. Saguaro fruits grow from the top of the plant and are roughly four inches long. They’re red, oval-shaped, and spiney.

The fruit of a barrel cactus will vary depending on the species, but they’re generally yellowish or greenish. They’re only about two inches across and taste quite bitter.


barrel cactus flower


4. Flowers

The saguaro flower is beautiful and white – no wonder it’s the state flower of Arizona. The flowers grow at the top of the plant and at the tip of branches. Meanwhile, the flowers of a barrel cactus are generally orange, yellow, or pink. They grow in a circle around the top of the plant when the plant is quite old.


saguaro flower


5. Root Systems

You might not get a peek at the root systems of the cactus you’re trying to identify, but if you did, you’d notice a big difference. Saguaro cacti have deep roots to support their height. The roots of a barrel cactus are shallow, spreading out from the base of the plant.

Both saguaro and barrel cacti will live to over 100 years of age. They’re important to the ecosystem, serving as food for animals and nests for some birds. With a bit of observation and practice, you’ll find telling the difference between these cactus species a snap!



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