New experiments, from South Africa to Texas

I use one particular phrase to describe my life these days: “I love living in the future.” I was already a correspondence junkie back then, but I’d have never guessed twenty years ago how many interesting folks I’d know from all over the world. Canada, Australia, England, New Zealand, Russia, Armenia, China…if someone offered me the chance to go back to 1991 and had the power to do so, I’d just smile and nod until the schlub turned his back, and then I’d beat him to death with a beanbag chair. (Now, if this opportunity were to stand on a hilltop some 150 million years back to watch the asteroid strike that produced the Tycho crater on the moon, I’d take him up on it. I may be crazy, but I’m not stupid.)

One of those interesting friends is Nerine Dorman from South Africa. Although best known throughout the world for her fiction, she and her husband are South African flora enthusiasts, and she forgets more about South African Euphorbia species in her sleep than I’d learn in a month of Sundays. One of these days, if money and time allow for significant travel, I want to stop by and say hello, and follow her and her husband for the next few days as they showed off local flora. I probably wouldn’t say a word the entire time, except to ask questions while taking frantic notes.

Many other friends describe my enthusiasm for sharing information with such words as “enabler” and and “pusher” and “damn you for making me empty my bank account.” In Nerine’s case, I can say the same thing about her. She introduced me to Silverhill Seeds in Cape Town, which in turn introduced me to what may become my nemesis or my salvation. That plant is Roridula gorgonias.

Both species in the Roridula genus are native to South Africa, thriving in remarkably similar conditions to those of Texas. Superficially, they resemble sticky-leaved carnivorous plants such as sundews and rainbow plants, but they don’t secrete mucilage such as these or dewy pines. Instead, the tips of their leaf threads produce resin. Mucilage allows the transfer of nutrients and digestive enzymes, but resin can’t, so naturalists thought for a century that any insects caught by Roridula were only incidental captures. Technically, since it also didn’t produce any digestive enzymes, Roridula doesn’t technically qualify as a carnivore, as it can’t digest and absorb any nutrients from captured prey.

The reality revealed itself relatively recently. Both species of Roridula have channels in their leaves, and both have unique species of assassin bug that live among the foliage. In the wild, the assassin bugs converge on captured prey in the Roridula leaves, having the ability to pass through the threads without sticking to the resin. They drain the prey, and then later defecate on the leaves. Those channels mentioned earlier trap the feces and allow the plant to absorb the nitrogen and phosphorus within, thereby making it a carnivore by proxy. That is, depending upon the expert you consult, and the discussion of Roridula‘s carnivory is quite the active subject within carnivorous plant circles.

Well, it’s time for the Triffid Ranch to jump into the fray. A fresh batch of seeds of R. gorgonias went into the greenhouse for germination, and since Roridula apparently loves the two things Texas summers have in abundance, heat and sun, I’m keeping close tabs on if and when they germinate. In three years or so, well, R. gorgonias should make a spectacular addition to lectures on odd plants, when these seedlings are full-sized. And until I can get to Cape Town and thank Nerine personally, I’ll have to settle for photos if this little experiment works out.

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