a couple months ago someone sent me an ask asking if Iâd ever heard of Boquila trifoliolata and I was like âno way. this canât be realâ and i looked it up and it was and I forgot about it until just now when my supervisor and I got sidetracked and I looked it up again to prove to her that itâs real and found out that not only does this plant vaguely mimic the leaves of whatever plant itâs vining on, it does it when it climbs on fake plants too so any theories about how it does it that include gene transfer or chemicals or touching it in any way are just out the window and those were like, the only theories the original researchers had about how it might be doing it. so anyway I am screaming and crying and whatnot
The more you read the better this gets â from Krulwich, Nat Geo 2016:
Boquila feels more like a cuttlefish or an octopus; it can morph into at least eight basic shapes. When it glides up a bush or tree that itâs never encountered before, it can still mimic whatâs near. And thatâs the wildest part: It doesnât have to touch what it copies. It only has to be nearby. Most mimicry in the animal kingdom involves physical contact. But this plant can hangâliterally hangâalongside a host tree, with empty space between it and its model, and, with no eyes, nose, mouth, or brain, it can âseeâ its neighbor and copy what it has âseen.â
(Artifical plant modeling & c. discussed in White & Yamashita, Plant Signaling & Behavior, https://doi.org/10.1080/15592324.2021.1977530)
Donât like this at all! Thank you!!
One theory from that above White & Yamashita paper is that Boquila does this using plant ocelliâa very basic type of eye! If youâre interested in a brief infodump about ocelli: Many animals have ocelli, like jellyfish and insects. Hereâs a picture of a wasp headâyou can see its two main eyes to the side, and those three dots in the middle are ocelli.
(Photo cred: Assafn, Wikipedia)
These ocelli donât form sharp images, but instead probably detect light and shadow for sleep patterns, directionality, flight stability, etc.
Some reptiles and amphibians also have a light-sensitive third eye called a parietal or pineal eye! Itâs similarly right on top of their heads. Again, theyâre not forming complex images, but instead use general light information to regulate other things. Itâs also why even tame reptiles may bolt if you reach at them from directly overhead, out of range of their normal eyesâthat third eye sees an incoming shadow and goes HAWK, RUN.
So with that in mind, plant ocelliâŚBasically they think the upper epidermal cells have evolved to have a particular convex dome shape that focuses light. I donât know what proportion of cells are ocelli, if itâs just some or all, but basically the leaf itself IS the âeyeâ.
Plant ocelli were first proposed over a century ago but they havenât been well studied since then. Cyanobacteria (a photosynthetic bacteria) focus light. Arabidopsis thaliana has been documented to recognize other Arabidopsis plantsâŚbasically when competing for resources, if the Arabidopsis recognizes itâs competing with other Arabidopsis plants, theyâll cooperate and move leaves so that they donât shade each other, ensuring each plant has access to nutrients. But if the competing plant isnât Arabidopsis, screw âem, theyâll shade it. Crepy & Casal narrowed this down to a light-based response, not just chemical identification, so itâs possible Arabidopsis is visually identifying friend from foe. At any rate, thatâs about the extent of plant ocelli research that I was able to find. So this Boquila thing is cool and weird.
What we donât yet know is how precisely Boquila is seeing the world. Boquila is clearly getting some level of resolution in order to be able to copy shape, size, AND color. Unlike an insectâs 2-3 ocelli, it has tons, so even crude data over a lot of inputs might lead to a pretty good picture. The paper also says the mimicry gets more accurate over time, so there appears to be some learning involved. I would also love to know if it has some equivalent of depth perception! If the target plant is near vs. far, does Boquila produce the same appropriately sized mimic leaf? Does it adjust? Theyâre going to keep studying it so hopefully we have some answers in a few years!
Anyway hereâs a picture of the variation of Boquila mimic leaves.
(Photo cred: Gianoli figure)
đ đą đ
