Types of Cactus: The Complete Beginner’s Guide to Cacti

types of cactus

Types of Cactus: The Complete Beginner’s Guide to Cacti

It can be challenging for life to survive the desert’s extreme temperatures and sun exposure. But, the greatest challenges often stoke incredible resilience! The desert’s hostility has resulted in one of the hardiest plants in the world: the cactus. There are many types of cactus plants in all shapes and sizes.

 

Cacti may thrive in the desert, but that doesn’t mean these succulents can’t also brighten up your home.  If you’ve got questions about the different types of cactus, we’ve got answers! In this article, we’ll cover everything you need to know about these resilient water-retaining plants.

 

 

What is a Cactus?

A cactus is a succulent belonging to the Cactaceae plant family. Cacti can come in various forms, but at their most basic, they consist of a water-storing body and areoles. The sharp spines that cacti are known for growing out of areoles. These are growths on the plant’s body, can also sprout flowers.

 

A cactus’s spines are actually leaves that have evolved to grow hard and pointy. Many plants have similar defense mechanisms, but they are usually thorns that grow from the stem. A cactus’s unique yet dangerous leaves are one of the things that make it different from other plants.

 

All cacti are succulents, but not all succulents are cacti. “Succulent” is not a species. It’s a term used to describe plants with thickened, fleshy, and engorged parts perfect for storing moisture. This is what makes cacti excellent at retaining water, as well as a shallow root system!

 

The cactus’s root system is usually 1-2 centimeters deep. When rain falls in arid climates, it evaporates quickly. The plant’s shallow roots allow it to soak up as much water as possible before it escapes into the atmosphere.

 

Cacti can also withstand temperatures that range from below freezing to over 100°F. Some species can even bear fruit. The pitaya (dragon fruit) comes from several cacti native to the Americas.

 

 

cacti in the desert with clear blue skies

 

 

Where Are Cacti Most Commonly Found?

The cactus is native to North, South, and Central America. These slow-growing, toughened plants are often seen in arid climates or regions with poor soil conditions. Though, they can survive virtually anywhere. No plant makes the best out of a bad situation like the cactus!

 

The cactus has been found in rain forests, on mountain ranges, and even in Antarctica! Though, not all cactus species can survive these conditions, as some only survive in moisture-deprived environments. Many cactus plants require periods of drought, and they could die if they become over-hydrated.

 

It is possible, yet rare, to drown a cactus. Though, it is even rarer for a cactus to die from too much sunlight. One of the cactus’s most advantageous traits in the wild is that it doesn’t disintegrate after extreme exposure to natural ultraviolet rays.

 

Though no plant fossils for this species have been found, it is thought that they originated roughly 25 million years ago. Experts were able to estimate this date because the cactus is mostly unseen in the Eastern Hemisphere. This suggests that it evolved after South America and Africa became separated.

 

Origins in South America

Almost all cactus species likely originated in northern South American regions. While the plants are almost entirely located in the Western Hemisphere, there is one exception to the rule. Rhipsalis baccifera is the only cactus that is not exclusively native to the Americas. Rhipsalis baccifera has been found in East Africa, Madagascar, and Sri Lanka. How is it possible that this single species exists outside of the Americas?

 

Experts are still unsure, but there are two prevailing theories. The first is that ancient birds ate the cactus’ berries in South America before flying to Africa and passing the seeds. The other theory is that 16th-century merchants brought the plants over as they sailed the East India Route.

 

 

a-bunch-of-different-types-of-cactus

 

 

How Many Types of Cacti Are There?

There are approximately 2,500 known species of cactus plants. These can range in color, size, and preferred region. Some cacti are native to rain-forests while others prefer tropical climates, but most of these sturdy plants are desert-dwellers.

 

Some members of the Cactaceae family can be hard to recognize as cacti. The plants we typically recognize as cacti (roughly 1,800 species) can be split into two groups: Opuntia and Cactoid. The remaining species are called Pereskia and Maihuenia, and they barely resemble their cacti cousins.

 

Pereskia and Maijuenia cacti are usually tree-like and round. Their woody stems may be covered in bark, and they often grow long-lasting leaves. Pear-shaped is the most common formation for Pereskia cacti. Maijuenia plants typically resemble a bonsai tree or prickly swathe of grass.

 

 

What Is the Most Common Type of Cactus?

Containing 1,800 of the plant’s 2,500 species, you’re far more likely to find Opuntia and Cactoid cactus plants than Pereskia or Maijuenia. There are many types of cacti in the Opuntia and Cactoid groups. The genus of cactus plants is often referred to rather than the species.

 

Some of the most well-known cacti are:

 

  • Cereus tetragonus: Native to North America, cereus tetragonus is commonly known as the fairy castle cactus. This is because its vertical stems of varying height resemble a fairy castle. This plant is easy to grow, making the fairy castle cactus a common choice for beginner succulent growers.
  • Espostoa: A genus of candle-like cactus plants covered in spines and white hairs. It grows delectable fruit that is safe for humans to eat.
  • Parodia magnifica: Colloquially called the ball cactus, these plants can grow 3-12 inches tall. It originated in and around Brazil. This cactus features yellow spines and flowers.
  • Ferocactus: This barrel-shaped cactus plant typically grows 5-6 inches tall and features “fishhook” spines. It sports showy flowers that may be pink, yellow, red, or purple, depending on the type of Ferocactus. The most popular type is Ferocactus glaucescens, better known as the blue barrel cactus.
  • Gymnocalycium mihanovichii: Gymnocalycium is typically referred to as the chin cactus, but  Gymnocalycium mihanovichii is called the moon cactus. The chin cactus has no hair or spines. The moon cactus is the result of a mutation that causes the cacti to lose chlorophyll. This exposes the red, yellow, or orange pigmentation of the moon cactus, resulting in stunning colors.
  • Astrophytum asterias: Also known as the star cactus, Astrophytum asterias is native to Texas and Mexico. The star cactus grows fruit and red-orange or red-yellow flowers that both feel wooly to the touch. The star cactus has no spines.

 

 

multiple types of plants in pots inside a nursery

 

 

What Are the Most Popular Types of Cactus?

Some cactus plants may be more common than others, but that doesn’t mean they’ll be the most popular. Different types of cacti gain notoriety for their aesthetics, such as pink flowers or a bunny ear-shape. These are some of the most popular cactus plants:

 

  • Echinocactus grusonii: The golden barrel cactus, Echinocactus grusonii is one of the most popular plants in cultivation. Even though it is endangered, you can spot the golden barrel cactus in many landscape designs as an architectural accent. The golden barrel cactus grows yellow flowers late in its life, and it has yellow spines.
  • Carnegiea gigantea: Known as the saguaro cactus, these plants are native to the Sonoran Desert in Arizona. The saguaro cactus is likely what you picture when you hear the word cactus. The sole member of the genus Carnegiea, the saguaro cactus can grow over 40 feet tall.
  • Mammillaria: Two types of this cactus genus are commonly seen. Mammillaria plumosa (feather cactus) and Mammillaria hahniana (old lady cactus) are native to Mexico and feature spherical shapes. The feather cactus grows yellow flowers and white spines. The old lady cactus sports pink-red flowers and spines covering its body.
  • Schlumbergera: The Schlumbergera cactus group refers to several plants. Its common name depends on its flowering season – It may be known as the Thanksgiving, Easter, or Christmas cactus! All Schlumbergera types can have red, pink, yellow, orange, or white flowers.
  • Opuntia: This genus is referred to as prickly pear cacti. There are various forms of prickly pear cactus plants, and the most common is Opuntia microdasys. Its common name is bunny cactus due to its round, flat appearance that resembles bunny ears.

 

 

Are Cacti Dangerous?

Cacti can be dangerous due to their sharp spines, though they’re not poisonous. With over 2,000 cactus types, some have learned to defend themselves. Spines can be barbed, hooked, or easily broken, staying in the skin and causing irritation.

 

Other spines might have bacteria on them that can enter the body and lead to infection. This is not a defense mechanism of the cactus! However, other animals may have come into contact with the plant and pricked themselves on its spines. If their bacteria is left on the spines, it could transfer to you.

 

No cactus plants grow poisonous fruit. In fact, cactus fruit is a large part of Mexican cuisine. Also, while some movies may make cacti seem like giant tanks of freshwater, avoid drinking cactus water or eating the plant. Many cactus plants contain acidic chemicals that can cause vomiting or diarrhea.

 

The cactus plant has just enough survival methods to thrive in harsh environments. Its spines and nauseating chemicals deter would-be herbivores from stealing their precious water.  After all, you don’t become one of the most resilient plants without knowing how to take care of yourself!

 

 

Can You Grow a Cactus at Home?

Yes, you can grow cacti from the comfort of your own home! Fortunately, you don’t have to traverse the arid deserts of Mexico or Arizona to find one of these hardy plants. Succulents have become a popular product for their beauty and simplicity.

 

Bring new life to any room in your home with some of these popular cacti:

 

  • Ferocactus: Small, spherical, and covered in spines, Ferocactus is a “barrel cactus” that grows yellow, red, purple, or pink flowers.
  • Schlumbergera truncata: All seasonal forms of Schlumbergera are well-suited for domestication. Though, if you’re going for aesthetic, cacti in the truncata group grow flowers sooner than its other group (buckleyi).
  • Myrtillocactus geometrizans: With the common name blue flame cactus, this is a large shrub-like plant that can grow 16 feet tall. You may want to plant this one outside.
  • Myrtillocactus cochal: Like its blue flame cousin, this “candelabra cactus” is a sprawling plant similar to a tree. It produces pale green flowers. Also similar to its cousin, Myrtillocactus cochal is best suited for outdoor growing.

 

Best Indoor Cactus Types

We all enjoy the luxuries of home, but our bodies crave nature. Introduce some cacti into your home for a low-maintenance and refreshing bit of greenery. These are the best types of succulents for indoor use:

 

  • Mammillaria: With white spines and two popular plants to choose from (feather and old lady cactus), Mammillaria is frequently listed as one of the easiest and most common succulents used at home for good reason.
  • Gymnocalycium mihanovichii: The moon cactus is the result of a mix between two other plants. Due to this, it needs a mix of bright light and partial shade. It is fine without water for extended periods of time and grows lovely funnel-shaped flowers that can reach 1-2 inches long.
  • Carnegiea gigantea: You may be wondering if this is the same saguaro cactus that is native to the Arizona desert. Indeed it is, but don’t let the “gigantea” in its name worry you. This plant usually reaches 40 feet in height, but it grows at a rate of roughly 3 feet every year. The slow-growing saguaro cactus should always get placed near windows, receiving full sun (this is a common phrase in the world of succulents, meaning 6 or more hours of direct sunlight every day). If you keep the plant outside, take it indoors if the temperature drops below 60°F.
  • Schlumbergera gaertneri: Also known as Easter cactus, this type of Schlumbergera grows red flowers. The Easter cactus will also produce red fruit when the flowers become fertilized!

 

Best Outdoor Cactus Types

Sometimes, we aren’t able to keep a cactus indoors. Whether the plant grows too tall or the home doesn’t get enough sunlight, there are still plenty of outdoor cacti options. These are some of our favorites:

 

  • Opuntia basilaris: Also called beavertail because of its wide and flat shape, this type of prickly pear cactus smells like watermelon in the summer. The defining feature of this cactus is its bright pink flowers. Even though it only grows 6-12 inches tall, the plant needs roughly 4 feet of horizontal space to stretch out. A beavertail requires full sun, making it ideal for dry gardens.
  • Myrtillocactus geometrizans: The slow-growing blue flame cactus can grow 16 feet in height, and it flowers in the summer. It sprouts greenish-white flowers along with delicious blueberries.
  • Myrtillocactus cochal: The candelabra cactus can be grown indoors or outdoors, though be cautious of its large size if you choose to keep it inside. Don’t expose this plant to temperatures below 25°F. Always allow it plenty of access to sunshine.
  • Echinopsis: Native to South America, Echinopsis is a wide range of cacti. If you’re looking for a cactus the size of a tree or a plant that can fit in the palm of your hand, you’ll find an Echinopsis cactus that suits your needs. Its defining feature is the large, gorgeous white flowers that it grows.

 

Easiest Cactus Types to Take Care of

Cacti are low-maintenance, but which ones are the simplest to care for? If you’re a person who’s always on the go, or if your living space has limited access to sunlight, these succulents are easy to grow and maintain:

 

  • Cereus: Cereus is a large family that consists of many cacti. There are various choices for each size and color preference, and one of the best for beginners is Cereus hildmannianus. Give the plant full sun and well-draining soil (it does not like to sit in water). Cereus is a special cactus because its flowers bloom at night.
  • Opuntia microdasys: The bunny ear cactus requires soil that drains quickly. Its flower will only bloom if it is given “winter” temperatures in addition to “summer” heat. The plant’s bunny ears can soak up sunlight all day long and withstand temperatures as high as 100°F. Provide Opuntia microdasys with 45-55°F of fluorescent light to simulate colder months.
  • Ferocactus: Who said beauty couldn’t be dangerous? Featuring long, hooked spines, this succulent is like a “Beware of Dog” sign for plant-lovers. It typically grows to about 6 inches, and, similar to the previous cacti, it needs fast-draining soil. Water the plant when you first pot it to cement it into the dirt. Add more water only if it is dry for long periods.
  • Mammillaria: This plant is known as the feather cactus because it is covered in what appear to be white, fluffy feathers. They are vast rows of spines, causing the cactus to look as if it were covered in cobwebs. The flowers that blossom can be white or dull pink, depending on the month. Mammillaria does well with normal cactus potting soil. You can fertilize Mammillaria during the growing season for maximum results. For this cactus, the growing season is mid-to-late summer.

 

 

desert nature scene with blue skies in the afternoon

 

 

Final Thoughts – Types of Cactus

Cacti are succulents, but they do a lot more than store water. They are defensive, adaptable, and capable of producing beautiful flowers. Each type of cactus plant has its own unique traits! From it be the color of its spines or the shape of its body, they’re all one of a kind. Whichever cactus you choose, it’ll stick around for a long time!

 

Related: Succulent Care: 7 Simple Tips & Tricks for Beginners

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