A good few years back I read an interesting reference book on flower physiological adaptations and catering to pollinators
One particular chapter dealt with what was colloquially referred to as the Japanese Death Orchid (differing from the Japanese flower of Death - ‘Tsubaki’). What this flower does to achieve pollination is nothing short of terrifying genius and uncanny sadism. Essentially, it lures crawling insects or those with a very weak flight ability into a chamber using traditional means of combined chemical and tactile stimulants. The chamber itself is (I think) not too dissimilar from those constructed by some of our native Asclepiads here in Southern Africa (Genus Ceropegia for example), with the main point of ingress at the top and the inner walls having a strange glossy sheen to them, which serves to disorientate and confuse insects inside the chamber in much the same way as a hall of mirrors would for humans.
The major difference however, is that this Death Orchid does not keep its Pollinia in a hidden compartment abutting the rim of the gynophore of the flower with an inbuilt escape thereafter, but rather, it holds these Pollinia upon a gynostegia-esque pillar far out of reach of the insects below. This pillar has, at its base, a row of pollen receiving stigmas which serve as no comfort to the poor insects inside, and the effect of the “hall of mirrors” and the channeling architecture basically results in each insect in the chamber succumbing to starvation and dying. This happens to countless numbers of these insects until such a point where the literal floor of bodies rises high enough to meet the top of the holy pillar, upon which a VERY lucky insect will enter the chamber, get to the pollinia and oils he came after, and then promptly leave via a bridging between the pillar and another small egress on the side of the flower.
With the pollinia attached to this lucky survivor, the flower then banks on the prospect that that insect will be one of the first to claw at the stigma ridden base of the next flowers column (only for it to of course die for all its effort!)
This story has truly captivated me and left me pondering just how and why this orchid evolved such a pollination scheme
Keep in mind that I’m reciting a few paragraphs from a book I read a good 4 years ago, so there may be some hyperbole and missing connections in what I’ve relayed but thats the just of what I can remember
Can any naturalists (Japanese or otherwise) tell me at the least what this Orchids scientific or Genus name is? I’d also really love to learn more about the evolutionary history of this plant so if anyone could give me some articles or podcasts to follow up on, I’d appreciate it!
Feel free to discuss possible causal factors and pressures which you think could’ve influenced this plant
I’m a little bit skeptical of the description of how the pollination works. That’s a really unlikely strategy to employ, would be extremely wasteful of pollen and other resources, and of the cavity was filled with dead insect bodies the final arriving insect would likely not actually come in contact with much (if any) pollen as it would be mainly be underneath the bodies, with only a small amount accessible to the newly arriving individual. It has the flavor of folklore.
I have a suspicion that it’s a misinterpretation of how a trap flower, like that in Trigonidium obtusum works (see linked paper below for descriptions and diagrams), where a specific pollinator is temporarily trapped in the flower (via a process and mechanism somewhat similar to what you describe), and eventually released.
If it’s not folklore, one possibility is that the flower evolved a particular trapping strategy for a specific pollinating species (many orchids are species specific in this regard), and that a newly arrived insect is also attracted orchid, but since the orchid didn’t evolve in tandem with this newly arrived insect it can’t utilize the flower’s release mechanism and dies there, to the detriment of both the plant and the insect.
Yes but bear in mind that Orchidaceae do not have individually isolated pollen grains amassed at scale but rather an amalgamation of these grains into sacs called Pollinia, which in the case of this flower sit atop the column I mentioned. Perhaps calling the organs at the base of the columns Pollinia receptacles is a better fit than stigmas then in that sense
I will check out your link to see if it matches this flower
EDIT: No this doesn’t sound like the flower I read about. I remember vividly that the flower prolonged entrapment in the chamber long enough for many insects to die, of that I’m sure
Thinking a bit more on it now, perhaps one of the mechanisms in this strategy is to reduce localized pollinator population density to a level which is most beneficial for short/ long range heterogeneic dispersal?
I didn’t say it was the flower mentioned in the article I linked, I said that I have a strong suspicion that the account you’re recalling is likely a misinterpretation of a different sort of flower/pollinator relationship, one that is more like the one in the linked article.
I don’t buy for a second that the flower evolved to be pollinated by killing a bunch of its potential pollinators, keeps the decomposing bodies in the same area as the pollen, and relies on some of the pollen to have happened to get churned up to the surface of the body pile in enough quality for a final insect to carry it off and then pollinate another flower via a similar process. No way.
There are some plants that do kill their pollinators, but those are special cases. The jack-in the pulpit, Arisaema angustatum, and the related Arisaema peninsulae, initially produce male flowers and the pollinating gnats fall in, but can escape to pollinate other flowers. Later in the development of the flower it shifts to producing female flowers and the escape hole closes. The trapped gnats can’t escape, but they do wind up helping the plant self-pollinate before dying. The lethal trapping is done by the female flowers only.
As it turns out Arisaema peninsulae is a Japanese plant, and is probably what you’re thinking of:
When the plants are small they only develop male flowers, which cover the gnats in pollen. The floral prison is too slippery for the gnats to climb out of, and their only escape is through a tiny hole in the chamber, before they can fly off and fall for the same trick on another plant. But as the plants grow larger, they develop female flowers and the escape hole closes and so gnats falling into the floral prison now become well and truly imprisoned. As they desperately try to escape they smother the female flowers with pollen, but with no escape route and no food, the gnats eventually die.
Hi , I’m japanese photographer.
I agree with earthknight san.
Arisaema have long inflorescences and has different flower structures between female and male flowers.
Only male flowers have holes in the bottom of the flowers.
It’s strange to kill a pollinia, isn’t it.
That could be the one that the book was describing, but I remember the chapter talking particularly about Orchids as was this case from what I can recall. Mind you, the book was certainly not fashioned or geared toward a description of scientifically sourced literature, but I remember vividly that it mentioned an Orchid in Japan that killed its ‘potential’ pollinators en-masse
I will try dig up the name of that book as best I can, if I’m lucky I may even find the excerpt in it that I read regarding this ‘Death’ flower. Then perhaps we can put this mystery to bed
Hi Light-Box !
I know it sounds very far-fetched but I assure you that what I read those many years ago ran atleast vaguely parrallel to what I described above (certainly not exact though)
I think the book also mentioned that this flower was restricted to a certain region of Japan (maybe even a certain island?). It’s a great shame that I cannot remember the plants scientific name or even the general locality mentioned in the book. All I know is that they mentioned it was an Orchid and utilized en-masse killing of insects (some of which might not even have been the intended pollinator?) to achieve cross-fertilization
Like I said, I will do my best to atleast remember or find the name of that book I read, then we’ll have a closer dig from there
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