sometimes I forget orchids grow on trees and I’m like. oh.
They do what now?
in the wild, most orchids grow on tree bark, a fact which will never not bring me a profound sense of delight
interestingly, orchids aren’t parasites–they are just harmless squatters hanging out with their arboreal buddies. it’s a form of commensalism–one organism benefits, the other neither benefits nor is harmed.
OK but orchids ARE parasites. They just aren’t parasites on trees. All orchids have this very bizzare lifecycle where they begin life as parasites on fungi. Here’s the rough strategy:
1. There’s a tradeoff between how much nutrients can be in a single seed and how many seeds you can make. On one end is the double coconut, the largest seed in the world weighing as much as a small child but each double coconut palm tree makes relatively few seeds per individual per season. OR. Make a fuckton of seed that individually cost very little to make. A lot of your small nonwoody plants chose this option, grasses, dandelions, any little weeds usually.
2. But there’s a limit to how far you can push this.
3. And by god orchids crossed it.
4. Orchid seeds are so fucking small they don’t have the energy stores to fucking germinate.
5. Orchid seeds are so small that they only consist of a few cells that haven’t decided who’s going to be roots or leaves yet.
6. And this is great! If you preferred habitat is in trees where the ability to disperse from one treetop to the next and find the right little spot on that tree to survive as a seedling for a few years is really hard. Lots of seed that can float on the wind and find just that spot is great for that.
7. But shit for actually, you know, being alive.
8. But orchids are crafty bastards.
9. Most plants try very hard not to be colonized by fungi, thats usually not good.
10. But orchid seeds just let fungi in.
11. And how the turn tables.
12. Because they just start eating the fungi back.
13. And this is where it gets weird.
14. Orchids are easily in the running for most diverse plant family at nearly 30,000 different species
15. And every single fucking one of them is like this.
16. And worse than that most of them are dependent on a single species of fungus to do this for them, so they produce millions of seeds just so that one might find the one right fungus.
17. And then after that anything can happen.
18. Some orchids are nice and start paying back their hosts onve they get big enough to phtotosynthesize with nice sugars.
19. Some orchids move on to as many as 30 other fungal species throughout their lives.
20. Some complete bastards keep being parasites after they are big enough to photosynthesize on their own. That’s right, a plant that can make its own food is stealing from something that lives on dead leaves.
21. Some orchids just never grow out of it, orchids have turned into permanent parasites more often than any other group of plants because they’re all parasites so becoming a full parasite is nbd.
22. And worse, most of these actually parasitize fungi that are symbiotic with forest trees that supply sugar to the fungi in return for better access to mineral nutrients, effectively making the orchids both parasites on the fungi and the trees, in a sense the whole ecosystem.
23. This leads to one more weird phenomenon. Mutant albino orchids unable to photosynthesize, of species that normally can photosynthesize, are often recorded as being able to reach maturity and flower without issue. because they just keep being parasites instead. Orchids can just. become parasites at will.
In conclusion orchids are just the weirdest fucking plants in the world. Technically all the above applies to this obscure group of ferns called the Ophioglossum family too. Same fucked up start out life as parasites and become independent (or not) later thing.
