At Triffid Ranch shows, one of the big draws, obviously, comes when I introduce passersby to the plants. All that I need to say is “Nearly everything here is carnivorous. Guess which ones aren’t.” Suddenly, it becomes a Gahan Wilson-designed Easter egg hunt, with everyone trying to see which plant didn’t consume flesh in its off time.
Euphorbia flanaganii, commonly known as “Medusa Head,” fools them every time. Between its tentacles and what appears to be multiple blunt-beaked mouths in the center, many of those passersby swear that it moves to follow them. When I have to admit that no, it isn’t actually carnivorous, they’re actually disappointed, because it makes an exceptional carnivore mimic.
E. flanaganii gets its common name from both its general reptilian appearance and the fact that it will grow to the size of a human head if left alone. It’s a member of what are referred to as medusoid euphorbias, a group of succulents native to South Africa. The entire Euphorbia genus is widely spread across the Old World, filling many of the niches filled by cactus in the Americas, and the variety of forms seen in the genus is simply breathtaking. E. flanaganii is one of many arresting oddballs, and it combines both ease in care with just a touch of danger. But I’ll get to that.
The structure of a typical medusa head is separated into the arms and the central caudex. As the plant grows, new arms form near the edges of the caudex, gradually spreading out as the plant grows, and the old arms shrivel up and die. Although a succulent, the medusa head needs much more water than would be acceptable or tolerable from most cactus or even most aloes, and it warns of a lack of water by gradually curling up its arms toward the center. It thrives under direct sun, and needs at least six hours of direct sun per day for decent health and growth. Best of all, once it’s situated and happy, it demonstrates its contentment with life by producing a ring of chartreuse blooms, each about the size of a ball bearing, around the caudex. The flowers don’t look like much under visible light, but they absolutely shine under ultraviolet lights.
Now, I mentioned “a touch of danger,” and that danger is why E. flanaganii shouldn’t be kept within easy reach of children or pets. The arms are tough and flexible, but if broken, they exude large amounts of latex sap. Said sap is about as toxic as that of other euphorbias: do NOT let it get in your eyes, and I highly recommend washing hands or other skin exposed to medusa head sap before getting said skin anywhere near your mouth. While none of the available literature mentions it, I’ve noted that the sap also has a phototoxic effect if it’s not washed off immediately. I had no reaction on my hand after getting some sap on my hand until I had no choice but to get out into the sun about an hour later. The resultant burn blister on the affected area taught me to wash my hands thoroughly afterwards.
On brighter subjects, E. flanaganii makes an exceptional container plant, and it can also be put into gardens so long as it’s protected from freezes. Even then, it’s remarkably tough. I had one head-sized flanaganii that I feared had died from exposure to the week-long deep freeze in Dallas in February 2011, and it didn’t make it. However, enough of the arms survived that they grew into new plants.
That’s the other bit of joy with working with E. flanaganii. Once it reaches a certain size, a mother plant will produce pups on the ends of older arms. The growth starts as a swelling at the end of an arm, and rapidly grows its own caudex and arms. After a time, if they don’t root on their own, the arm shrivels and allows the pup to roll away, where it rapidly grows if given access to soil and water. If you’re not careful, you can end up with a whole greenhouse full of them.
While they give no indication of ever becoming an invasive plant, medusa heads seem otherwise perfectly suited for North Texas conditions so long as they get watered regularly during the worst parts of summer. They don’t sunburn easily. They have no insect pests in the US, at least so far as I’ve noted, and even stink bugs stay away from them. They require good drainage, but they’re not fussy about soil conditions otherwise, and they grow well over a wide range of pH levels. They don’t seem to be susceptible to any parasites or diseases seen among other succulents, and they require only the occasional dash of fertilizer. Oh, and when mulched with Star Wars action figure parts, particularly Boba Fett and stormtrooper figures, people tend to go nuts over them.
— Many thanks to South African horror writer Nerine Dorman for turning me onto the joys of the entire Euphorbia clan. She and her husband have been raising South African succulents for years, and she’s forgotten more about the euphorbias than I’ll ever learn.