Curious about the context? Check out the introduction.
Some of the content in this series appeared, in much shorter form, in Gothic Beauty magazine.
Step 5: Set off its traps with your finger.
Home improvement stores are dangerous places to be when you’re married to the Czarina. On any given day, she has one interesting project or another that’s cooking, from making new necklace displays to building mobile bead tray racks, and that means the folks at the local Home Depot and Lowe’s stores know us on a firstname basis. If she’s not buying up PVC pipe and walnut molding, I’m buying up epoxy putty and Gorilla Glue. What’s scary is that I can exclaim, in my best Red Green voice, “Today on Handyman’s Corner, we’re going to reverse the polarity of the neutron flow!”, and I hear loud and robust laughter from the checkout clerks. At our local traditional hardware store, I had to explain who Red Green was, and this was a store that was hosting an autographing and photo session.
Anyway, I tend to wander through the garden section at those big stores as well. Most of the time, it’s to rescue some poor neglected Dendrobium orchid or random succulent in the deep discount rack, but every once in a while, it’s to see the latest trends in carnivorous plant packaging. Not in variety, nor in propagation methods, but in packaging.
As mentioned a while back, my father was, before he retired, a packaging engineer of some reknown. Every time you see one of those aluminized Mylar packages of Doritos or Fritos in an office cafeteria vending machine, you’re looking at my dad’s work. As also mentioned a while back, the family was hoping that I’d be another Larry Ellison instead of a Harlan Ellison; not much rubbed off from the family’s fascination with engineering. However, just enough rubbed off that I can appreciate the commercial horticulture trade’s attempts to protect its Venus flytraps.
One night, I saw a beautiful example of this in action. I was in a Home Depot picking up some extra garden hose gaskets, and peeked in the garden section. That section was hosted by a girl who was maybe 19 if a day, and she was standing in front of a big rack full of Venus flytraps. These were in those sad plastic containers that were popular at the time, with one clear dome atop a flimsy clear cup, and she was popping them open one at a time. I stepped closer, and I realized she was setting off every trap on each plant with her finger. Once every trap was closed or closing, she recapped the cup and moved on to the next one, and when she saw me, she waved me over. “Watch this,” she said, as she set off another trap.
At that point, I winced. “You really shouldn’t do that. That’s not good for the plant.”
“Oh, it doesn’t hurt it,” she said, going back to molesting the flytraps. Seeing from her badge that she was the garden center manager, I decided that arguing with her was a waste of time, and I simply left.
Right there, with that manager, the entire fascination with flytraps stands revealed. Here is a plant that closes up mouth-like traps, not under any touch such as with Mimosa pudica, but under the specific stimulus of setting off trigger hairs within the trap. The Venus flytrap can count and keep track of time, as the trap won’t close unless two of those trigger hairs are set off at the same time or one is stimulated twice within ten seconds. Even better, if the trap was triggered by something inedible, such as a raindrop or a twig, or by something too big for it to catch and hold, the trap gradually re-opens over the space of hours or sometimes days.
Well, that’s the popular legend, and it’s all true. It also leaves out a lot of particulars that can kill the plant if ignored.
Firstly, when looking at a Venus flytrap, it’s easy to see the trap as something growing off the end of a leaf. In actuality, the trap is the leaf, and the “leaf” is actually what’s called a petiole. Although the leaf’s secondary adaptation is to catch and digest small prey, it’s still a photosynthetic surface, no different from a maple leaf in that regard. The reason why flytraps just sit there and wait for prey is because, like all other plants, they’re relatively low-energy organisms compared to animals. They can afford to wait because their main source of energy comes from the classic conversion of sunlight, carbon dioxide, and water into sugars and connective tissue.
What this means is that if a trap gets set off with prey inside, the plant benefits from the nitrogen and phosphorus in the bug being digested (possibly along with trace elements, but I haven’t found any research to ascertain what else they may absorb), but the actual photosynthetic surface of the leaf is out of commission until the digestive process is complete and the trap re-opens. If the trap closes without capturing prey, yes, the trap will re-open. The problem is that the return on captured nitrogen just barely makes up for the energy expended in re-opening it, and an empty trap doesn’t even get that. Close enough traps at the same time, and wondering why the plant dies is like holding you down, clamping your nose and mouth shut, and wondering why you’re turning purple.
Incidentally, this also ties into a regular complaint I hear about how “my flytrap won’t eat.” The closing process is a very ingenious use of topography, but opening is a simple growth process. Picture it as opening a mostly-closed door by shoving wedges into the crack between hinges until it pops back open. Add enough wedges, and the door can’t shut at all. After a flytrap’s trap has been set off about four or five times, the trap curls slightly and now acts as nothing but a photosynthetic surface. In that regard, it’s perfectly suited for its job, but no force on earth or heaven will get that trap to close ever again.
This doesn’t explain why flytraps kept in colder conditions, such as those going into winter dormancy, are so loath to close, but it doesn’t have to. Between lower temperatures and lower light levels during winter, any trapped prey in a dormancy-bound flytrap will rot before it ever gets a chance to be digested, so don’t worry about feeding your flytrap over the winter. Giving it plenty of light before snow or ice kill off the current year’s traps is good enough.
Next: Step 5 – Feed it hamburger.
