To Spine or Not to Spine: A Succulent Journey

By Emily Hall (November 2022)

When I first began collecting succulents, it was all about the spines. Perhaps my Midwestern suburban life was too dull, and I craved the kind of danger that only plants that could take out an eye would provide. Perhaps I felt a quiet kinship – don’t we all secretly know that, if pressed, we are as dangerous as a barbed spine? For whatever reason, it was cacti for me, and the spinier the better.

For love of spines, my succulent journey began with cacti exclusively. I was a purist. A cactus snob? Perhaps. While an occasional Euphorbia obesa might tempt with its unique pink and green pattern of lines, I resisted its spineless hide. And convergent evolution aside, that Euphorbia aeruginosa has latex-weeping thorns, not spines. Adeniums? If I wanted a tree, I could grow a proper one in the yard. Haworthias: ubiquitous and overhybridized. Crassulas? So dead common you can even buy them at Home Depot. I wanted rare, colorful, dangerous spines.

Spines are the modified leaves of the cactus, sprouting from highly modified branches called areoles. Spines evolved to benefit cacti by reducing air flow across the cactus body to decrease evaporation, collecting water in their specialized grooves on foggy or rainy days in arid habitats, providing shade from the brutal sun exposures where they often grow, and protecting the plants from predators with their fascinating variety of shapes: straight, curved, flat, round, hair-thin, bristly, woolen, needlelike, or awl-shaped and, in some cases, hooked or barbed.

My Favorite Spines

Following are a few of my most beloved spiny plants:

Neoporteria coimasensis, with its dark central spine spiking out from amongst a ring of gently curved radial spines. The strange purple body is an aesthetic plus.

Opuntia pusilla, my island green gem. East coast beachside landlords thank me for digging these plants out of the edges of their rental properties before fragile, errant pads embed themselves in the equally fragile, errant feet of unsuspecting barefoot children and adults alike, or mat themselves into dogs’ fur so deep that they have to be cut out.

Their arrow-straight, rust red spines can grow nearly 2 inches long, with as many as three closely spaced, heavily barbed central spines jutting from areoles puffing thick into an off-white dome of eagerly protective glochids.

Grusonia invicta, the cactus that I coveted the longest for its fat, deeply ridged, dewdrop-shaped pads covered in wide, fuchsia-red daggers that gradually fade to a dignified grey as they mature.

I scrolled through Etsy ads for hours, finding only single-pad, lightly rooted starter plants for upwards of $40. A visit to Drummond Nursery on a magical November day two years ago finally yielded success. There! Amongst the outdoor winter hardies in front of the last greenhouse door on the right – three magnificent G. invicta, each at a very reasonable price. Two of them are now prizes in my collection.

Caring for Cacti

Caring for cacti can be as painstaking as you want it to be: researching native climates for exact temperature parameters, mixing custom soil to mimic the mineral plains of the coastal Atacama to the sandy Sonoran desert slopes, reading endless Web articles on the exact Kelvin range of LED grow lights for that winter sunshine boost in our cold and cloudy clime.

Caring for cacti can also be painful. My husband has diligently excavated countless opuntia glochids from my tender hands and arms with a needle and his finest tweezers, peering through his jumbo, desktop-mounted magnifying glass to search out the tiny, barbed, maddeningly itchy pricklers and prying them from my flesh while I held my breath to stay still.

It turns out that I am allergic to my treasured Trichocereus terscheckii, its deeply curved yellow sabers leaving me with an aching, swollen lump for several days should I stab myself or even slightly bump it.

There have been not just physical wounds, but emotional ones, too. The sudden rot and collapse of a rare Copiapoa dealbata, the careless and irrevocable sunburn scars on a Thelocactus fossulatus, eventually condemned to the trash. Clearly I am not so dangerous as a spine, for the plants’ ailments hurt my heart.

Softer Collection

And so it has gradually happened. I have softened. My collection has softened, too. A row of Adenium obesum, spineless and charming, now sits in the front line of my south-facing kitchen window. Instead of spending his time glochid-mining my fingertips, my husband is currently macraméing jute plant hangers for my exploding Senecio collection – long strings of tiny watermelons, raindrops and pearls. Sansevieria, Gasteria, Echeveria – bring them on. They’re easy and gentle and kind. Adromischus, Faucaria, Kalanchoe – yes, please. I repent all my previous snubs.

My most recent obsession? Haworthias, particularly the ones with leaf windows, glowing pale milky white in the sun. Through these translucent panels, sunlight more easily reaches the photosynthetic tissues within. In the wild, only the epidermal windows peek above ground, the rest of the plant remaining hidden beneath the soil surface to protect itself from desiccation by wind and sun.

Their white flowers are tiny, but reliable – a cheerful relief when it’s snowing outside – and blossoming from ridiculously overlong, foot-plus stems that provide my cat, with whom they must share their window shelf, hours of delight. (Happily, they are non-toxic to felines.) I love the way that a little too much sun or far too little water will turn their bodies from green to a red/purple far deeper even than new Opuntia pusilla spines … and far less stabby.

Haworthias are native to South Africa, Lesotho, Eswatini, Mozambique and Namibia. But on a good day, you can even find them at Home Depot.

Interactive:

Visit the Henry Shaw Cactus and Succulent Society Member Forum (https://hscactus.org/member-forum/) in the Plant Forum category, “Spine Stories” post, to share a name/pic of your favorite spiny cactus, deepest betrayal by spine or other spine story.

Sources:

Plant Snap – https://www.plantsnap.com/blog/why-do-cacti-have-spines-4-reasons-cacti-are-spikey/
Discover Magazine – https://www.discovermagazine.com/planet-earth/this-is-why-some-cactus-spines-are-so-hard-and-painful-to-remove
Wikipedia – https://en.wikipedia.org/wiki/Haworthia