10 things you may not know

The amazing world of cacti

They’re iconic. Think cowboy shootouts in desert landscapes dotted with saguaro cacti. Typically growing up to 50 feet tall, saguaros are the biggest cacti in the US. They’re found in eastern California, Arizona and Sonora, Mexico, and are said to be able to absorb up to 200 gallons (US) of water when it rains. Imagined as humans transformed into plants in traditional storytelling, they can look like hulking figures with ‘arms’. 

They’re drag queens of the plant kingdom. In spring, cacti transform themselves with riotously colourful scented blooms that emerge from areoles. These unique and sometimes hairy areas on their ‘skin’ are also where spines form. Often their off-the-scale red, orange, pink, blue and yellow flowers last just hours or days. Many white-flowered bloomers glow up only at night. More than long enough to perfect a tongue pop 😉 

They’re life-sustainers. 

From turkeys to tortoises, cochineals to lizards, hundreds of wild critters and domestic animals depend on the nutritious fruit, stems, and roots of cacti for food and water. Besides cooking with them, Native Americans use cacti as medicine. They’re believed to be effective for diabetes and arthritis. In the lava-scape of the Galapagos, candelabra cacti provide food and shelter for Darwin’s finches and Galapagos doves.

Chollas Cactus field in the desert of the Joshua Tree National Park
Chollas Cactus field in the desert of the Joshua Tree National Park

They are pollinated by bats. As well as by hummingbirds, bees, and moths, in return for their lovely nectar. When bat numbers drop, as they did in the eastern US by almost one-third between 2000 and 2015, ecologists consider the implications for other species, which may include cacti. Even if there’s a seeming abundance of these winged mammals, whose colonies can contain millions.

They’re extremely diverse. We’re talking a smorgasbord of body types: tree-like, columns, globes, fleshy pads, with waxy skin that’s ridged, smooth, with / without prickles or leaves, in greens, yellows, reds, even blue. They grow on clifftops, in rainforests, on mountains, as well as deserts, in soil, on rock and other plants. The smallest, Blossfeldia liliputana, is less than an inch fully grown. The tallest freestanding cactus, the Mexican giant cardon, can reach 60+ feet. One or two, like the peyote, contain mescaline and are known psychedelics…

They make a great snack. Ask any Mexican taco street vendor. They may tell you that nopales pads from the prickly pear cactus fried with onions and garlic and covered in gooey white cheese are to die for! (Canned versions are available.) Dragon fruit from the native Hylocereus undatus cacti is also widely eaten by humans and cultivated on farms in tropical parts of Asia. Cactus jams, syrups and various types of alcohol are also made.

A pitaya or pitahaya is the fruit of several different cactus species indigenous to the Americas. These fruits are commonly known in English as "dragon fruit"
Hylocereus undatus

They’re hardcore survivalists. 

Thought to have been around for 110 million years, pricklies include almost 2,000 species. Almost all are native to North and South America, including Mexico, the most cactus-rich country in the world. Now they’re found in Europe, Africa, and Australia. Some grow to be hundreds of years old, can go for a year or more without rain and withstand extreme heat, wind, drought, even a dusting of snow. Eat your heart out Bear Grylls!

In parts of the world, they’re invasive pests! 

Take the prickly pear cactus in Australia or Africa, which was thought to have been introduced by colonialists in the nineteenth century to create natural fences. It’s overwhelmed many native species in the Outback and is causing problems for farmers. In Kenya, communities are fighting back, grinding up the thorny pads to create energy for homes from biogas.

Almost one-third are threatened with extinction. Sadly, it’s true. Despite most species being protected by CITES, the international treaty that regulates trade in at-risk species. According to the International Union for Conservation of Nature, much of the national and international trade in cactus plants and seeds is illegal. It’s believed to affect 47% of threatened species. European and Asian collectors are the biggest consumers. 

Did we mention the spines? Soft / feathery / bristly / needle-like, cactus spines (aka spikes!) are modified leaves on their stems. They stop the cactus getting sunburned, reduce water loss and protect it from animals, which is crucial if said prickly is the only water source for miles. Since spines can’t photosynthesise, the stems do that instead. The aptly named hedgehog cactus, in Chile’s Atacama Desert, has some of the longest spines. Those of the fuzzy-looking teddy bear cactus are said to be as sharp as glass. That’s one big OUCH!


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