Wanna hear something mind-blowing? There’s a good chance every orchid flower you have ever seen was actually upside down.
I recently learned about resupination, which is a term used to describe plants that rotate their leaves or flowers upside down… err right side up, technically? This is practically the norm for orchid flowers. I was going to post an orchid time-lapse video that showed this (as I originally thought they all have funky twisting patterns as they physically open), but I looked and looked to no avail. So, after doing some research, it seems that this step can occur before or during blooming. (It kind of reminds me of how humans can have situs inversus, although I’m sure those individuals with it are very glad it happened in the womb.) Now, what I want to know is if this occurs during bud development, or just in a stage before the blooming is outwardly visible to bystanders but after the bud is already developed. I can confirm that this does not happen after opening, though.
*shrugs*
Next time I meet a botanist or orchid specialist in real life, I’ll make sure to ask.
The last time I talked about orchids, I went over basic anatomy. I mentioned that the labellum is that jazzy decorative petal, used in attracting pollinators and, in some cases, acting as a place for said pollinator to land (our boy Darwin wrote this, and apparently he has an entire book called “Fertilisation of Orchids”). If the original placement for the petal was facing upward, it makes sense that evolution would favor a way of getting that to face downward. Since nearly all orchids have this trait, it means it is probably pretty crucial to their survival and/or was found in a common ancestor. Another thing to note is that since those orchids are clearly thirsty for some cross pollination (over self pollination, which seems a lot easier to do given their anatomy), it probably favors this, as well.
Now for the cool part. There are some orchids that are non-resupinates, and they can do this in two ways according to what I have read. First, they can just, well, not turn 180 degrees. Makes sense, right? Second, they can turn 360 degrees. I assume it must be easier for them to just add the extra turn than to remove/stop whatever causes the first turn. But I am just still blown away that this is how they can do this, even if it isn’t really optimal design I.M.O.!!! I want to know if any species would then turn 540 degrees if resupination was again preferred. I was also questioning why some orchids wouldn’t want to be upside down, and it seems that this has to do with their preferred pollinators and vapourization of fragrances. I also personally believe temperature regulation may be involved, although this could be part of the fragrance argument according to an article by Dr. Joseph Arditti. Also according to him, better sunlight could better expose nectar guides.
Actually, I’ll add that on this post, it is totally worth the read. Below is a link to the article. I also included the DOI. It’s only like a page and a half, but it does a really good job going through resupination basics. It also talks about some hormones involved in the process.
https://revistas.ucr.ac.cr/index.php/lankesteriana/article/view/23025
DOI 10.15517/LANK.V3I2.23025
I also wanted to add some photos of non-resupinate orchids, but I feel mildly uncomfortable with posting someone else’s photos here, so I am just going to provide a few species names, and y’all can look them up on Google if you are bored and wanna see what they look like.
–Calopogon tuberosus
–Prasophyllum elatum
–Epidendrum secundum
Happy reading,
-Beppa
*This is a republished post due to a domain change.*