Prickly Pals: The Many Types of Cactuses

Discover the fascinating diversity of the cactus family. This article explores common types of cactuses including prickly pear, barrel, saguaro, hedgehog, Christmas cactus, old lady cactus and more!

Look around any desert landscape and you’re sure to see their distinctive spiny silhouettes – cactuses are some of the most fascinating and unique plants in the world. With over 1,750 different species ranging from tiny pincushion globes to massive columnar trunks, there’s an incredible diversity to explore in this drought-tolerant plant family. Let’s take a look at some of the most common and interesting types of cactuses out there!

1. Prickly Pear Cactus (Opuntia)

One of the most widespread genera is the prickly pear cactus (Opuntia), consisting of over 200 different paddle-shaped species. Originating in the deserts of North and South America, these densely-spined succulents can reach up to 23 feet tall.

The iconic beaver tail cactus is one of the most common prickly pears found in gardens and landscapes. Its blue-green pads form low mounds covered in harmless tufts of hair-like spines called glochids. In late spring, showy yellow or red flowers bloom among the pads.

Prickly pears produce edible reddish “tuna” fruits that have been harvested since ancient times. The fleshy pads or “nopalitos” are also edible and a staple ingredient in Mexican cuisine when prepared properly after removing the spines.

2. Barrel Cactus (Ferocactus)

With their rounded, barrel-shaped bodies densely covered in spines, ferocactus cactuses like the barrel cactus make for some of the most distinctive desert sights. Originating primarily in the Southwestern USA and Mexico, most species grow only 1-3 feet tall but some giants can reach over 10 feet!

These formidable globular stems have evolved to conserve every possible drop of moisture received from scarce desert rains. Their thick, ribbed bodies allow for maximum water storage when it’s available, tapering to a sturdy base to provide stability as they grow taller over decades.

The heavy spines of barrel cactus protect them from thirsty animals looking for a drink. Flowers appear in a vibrant ring around the top of the plant when mature, opening at night to be pollinated by bats, moths or other nocturnal creatures.

3. Saguaro Cactus (Carnegiea gigantea)

Perhaps the most iconic desert plant is the saguaro cactus, the largest cactus species in the United States. Exclusively found in the Sonoran Desert of Arizona and northwest Mexico, these giant columnar cacti can grow over 60 feet tall and weigh over 10 tons when mature!

Saguaros may appear lifeless, but they actually have a surprisingly fast growth rate of up to 8 inches per year when young. However, these giants take 50-100 years before displaying their first branch or blossom at the top. By the time a saguaro dies of old age around 150-200 years, it often has multiple arms reaching skyward.

In early summer, spectacular waxy white flowers bloom at night and remain open for just 24 hours to be pollinated by bats, birds and other desert creatures. If pollinated successfully, the flowers develop into bright red fruits that have long provided food and hydration to indigenous peoples.

4. Hedgehog Cactus (Echinocereus)

On the opposite end of the size spectrum are the diminutive yet fiercely spiky hedgehog cactuses. These small globular to short cylindrical cacti never grow more than 1-2 feet tall, covered in dense spines reminiscent of a little porcupine.

Echinocereus species range across the Southwest USA into Mexico. One of the most widespread is the claret cup hedgehog cactus, which features large red to purple blossoms emerging from the spiny crowns in spring.

Like most cacti, hedgehogs have adapted incredible methods to endure harsh desert conditions. Their dense spines prevent moisture loss, while the plump barrel stores water during dry periods. Some species go dormant in summer when temperatures soar too high.

5. Christmas Cactus (Schlumbergera)

While most cacti species evolved for arid desert conditions, the Christmas cactus actually comes from the humid rainforests of Brazil. A popular houseplant, schlumbergera feature flat green stem segments with rounded bristles rather than sharp spines.

Christmas cacti get their name from their tendency to bloom around the winter holidays. Their delicate tubular blossoms come in shades of pink, red, orange, yellow and white depending on the variety. The colorful flowers make them a favorite gift plant during the holiday season.

Unlike their desert counterparts, Christmas cacti require evenly moist soil and can’t tolerate drought conditions. They go dormant in winter and must experience cooler temperatures of 50-55°F at night to set flower buds for the following season.

6. Old Lady Cactus (Mammillaria)

The mammillaria genus contains some of the most distinctive ball-shaped cacti, featuring striking patterns of densely packed tufts or tubercles across their globular bodies. Also known as pincushion, powder puff or old lady cactus, these spiny spheres make for fascinating additions to rock gardens and potted cactus collections.

Native to the hot, dry climates of Mexico and southwestern United States, mammillarias generally have solitary globose bodies ranging from just 1-2 inches in diameter up to over 1 foot wide. Many donned with an impressive array of hooked spines for protection against herbivores.

In spring, striking ring-shaped cactus flowers often appear around the crowns atop the tubercles. These blooms come in shades of red, yellow, white and pink, each with a unique intricate center pattern.

Old lady cactus varieties are a favorite for collectors who can amass stunning geometric displays with their dense coverings of spines and wooly tufts. Just be sure to wear thick gloves when handling them!

7. Orchid Cactus (Epiphyllum)

At first glance, the orchid cactus looks more like a succulent than a prickly desert dweller. Also known as the leaf cactus or epi-cactus, these unique jungle cacti feature flattened stems resembling large fleshy leaves rather than the typical round or cylindrical shape.

Native to the forests of Central and South America, epiphyllums often grow as epiphytes clinging to tree branches and trunks like orchids. Their leaf-like stems help maximize surface area for photosynthesis under the shaded rainforest canopy.

Orchid cacti bloom at night, producing some of the largest and most fragrant blossoms of any cacti species in brilliant shades of red, pink, yellow and white. Their exotic, showy flowers unfurl in series over the course of several weeks.

While they require more humidity than desert cacti, epiphyllums make wonderful hanging basket or potted plants that are surprisingly easy to grow indoors when you understand their tropical needs.

There’s no shortage of incredible spine-tingling shapes and sizes when it comes to the diverse cactus family. From towering giants that inspired the imaginations of cultures past, to tiny pincushion spheres packed with dense spines for protection, these succulents have amazing adaptations for survival in some of the world’s harshest environments. So next time you encounter a prickly pal in the wild or at your local nursery, take a moment to appreciate the unique natural history and beauty of these remarkable plants!