Cactus vs. Euphorbia
The easiest way to tell them apart is to cut them open. Or look at the spines. Either way you figure it out, keep protected when pruning.
“I spent Valentines Day crying and in pain from burning eyes so bad I had to call the paramedics. That day I pulled lantana that had interweaved into pencil cactus. I was so careful not to get any cactus sap into my eyes. It was awful pain. The paramedics said just to keep your open eyes under running water. It took about four hours. Now I am afraid of my garden.”
My heart goes out to Kurt, an innocent gardener who tangled with Euphorbia tirucalli, which is not a cactus but an African Euphorbia called pencil tree….
Like all Euphorbias, this one contains caustic white latex sap that would burn the lips of any animal that tried to eat the moist, succulent flesh….
Nick the skin of any Euphorbia and you find big white drops of latex come pouring out. Nick a cactus and the sap is clear or green. Sap color is key to telling a Euphorbia succulent from American cactus….
One experience of mine proved that flecks of latex that landed on the forehead or in your hair can later travel in your sweat to contaminate eyes, nose and mouth. Wipe it away and it’s on your hands too. Another gardener contaminated his eyes in the evening by taking off the shirt that he wore when working with Euphorbia that day.
It doesn’t take long to learn the lessons of the Euphorbia. By the way, E. tirucalli is a beautiful houseplant as well as looking benign while being one of the more caustic of the Euphorbias so it doesn’t mix well with children.
Here’s a photo for your fear and enjoyment.
And here’s one in habitat.
Big! Why, that looks like a tree. Everything grows bigger in Africa. But keep it inside in the Bay Area since it’s not hardy at all. It will turn to slime with one cold night.