Cactus | Nature Adventure

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Biology

A cactus is a very special kind of plant natively found in North, Central and South American deserts. There are over 2,000 species of cacti that vary in size, shape, and color; from the tiny Blossfeldia, no bigger than a penny, to the giant Saguaro that can weigh more than a car!

Cacti are specially adapted to live in places where there is very little water and a lot of sunlight. Unlike other plants in dense jungles and forests, cacti don’t need to compete for light; meaning that they don’t typically have wide, flat leaves like we’re used to seeing. Instead, most cactus want to minimize their surface area so they don’t burn in the sun! This means that they either grow tall and thin, or are short and round. High winds are also common in the desert, and taller cactus are more at risk of being blown down!

While not all succulents are cacti, all cacti are considered succulents. This means that their bodies are thick, rubbery, filled with water, and have a waxy shell that almost feels fake! Some cacti have ephemeral leaves, which are small and only last for a short time before falling off, while others have permanent leaves with a similar rubbery texture. Cacti also have spines, which are a type of modified leaf! They’re not used to collect sunlight, but to protect the big body of the cactus from animals.

Since water is rare in the desert, cacti have evolved a few ways of surviving long droughts. They are able to enter long periods of dormancy, where they do not grow at all and need less water to survive. Their roots are also shallow and grow a long way away from the main body, allowing them to soak up as much rain as possible when it does fall. Finally, the whole body of the cactus can pull moisture out of the air, allowing them to drink from the fog!

Ecological Importance

The cactus can provide habitats and food for many animals in the desert, including birds, coyotes, insects, tortoises, and even camels! They are important sources of water and nutrients in an otherwise empty landscape, and this makes them very valuable for sustaining life. Cacti can even provide homes for animals after the plants have died, so it's important not to disturb fallen cacti when you're out for a walk!

Many people think that drought is what makes a desert, but that's not the full story. When land turns into a desert, it's called desertification; and while drought can speed this process up, it's usually caused by deforestation and too much livestock being housed on the land! When these problems are combined with climate change, more and more places in the world are starting to become deserts, and our North and Central American deserts are starting to lose any plants and animals they have. Reversing this process has to be done quickly, but for areas that have been empty of plant life for a long time, this might no longer be possible!

With so many cactus species being endangered due to illegal harvesting, the possibility of re-growing or protecting these desert areas from getting worse is getting harder to do. Cactus grow slowly, and are sensitive to global warming. If we start losing cacti, the chances of keeping our deserts livable drops significantly!

Did you know?

Cacti are used by people just as much as they are used by animals. Throughout history, we have found ways to use cacti as food, medicine, and even for making tools!

The prickly pear (Opuntia stricta) is one of the most well-known edible cactus species. The fruits are those little red bits growing on top of the cactus, and they are either eaten raw or used to make jelly, while the stems (or pads) are often grilled or diced! These cacti are also grown as food for domesticated animals, like cattle, in environments where growing hay can be difficult. Dragonfruit, or pitaya, is another type of commonly eaten cactus fruit!

Cacti also have a lot of medicinal uses, and are being studied in multiple fields of medical technology. Eating cactus can lower cholesterol and protect your heart, and could even help manage diabetes. Traditionally, cactus flowers, fruits, and stems have all been used in folk medicine to treat everything from cancers to infections. Scientific studies are still ongoing about what the benefits might be, and how we can use them to create better medicine!

Aside from food and medicine, though, cacti have been used to make all kinds of things. Barrel cacti spines were once used to make the needles on phonographs and fish hooks, for example! And today, many people enjoy keeping cacti as houseplants because of their low water requirements. However, some people like them a little too much, as many cactus species are now threatened with extinction due to people illegally harvesting them in the wild!

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