The elusive Plant Species X from Ark is a plant and a defensive turret in one. Since its introduction into Ark, it has changed little, except for where you'll find the seeds to grow it!
In the early days of the game, you could get seeds by harvesting the bushes on top of the mountains. But that certainly doesn't seem to be the case anymore. I've tried for over 6 hours to see if this still works, and while I found a ton of Rare Flowers, I didn't find any Plant Species X Seeds.
So where are they? Plant Species X now lives in the Swamp Biome where it was apparently always intended to live. And instead of harvesting random bushes to get the seeds, your best bet now is to find a live specimen and harvest that by hand. It is possible to find the odd rare Plant Species X seed by harvesting certain bushes in the swamp, but this puts you in the bad position of not being able to see some of the swamp predators as they approach you. That's because they will be concealed in the tall vegetation.
Sound dangerous? It is. But don't worry, the Plant Species X you find in the wild is not weaponized and can be found on the edge of the swap. This makes it possible to zip in, get some seeds, and get back out.
That also means that the Plant Species X does not quite look the same in the wild as it does fully grown in a Crop Plot. Don't worry; I've got a handful of screenshots and, a bit further down the page, GPS Coordinates for you.
Remember, you get the best results harvesting the wild plant by hand! And no, it doesn't hurt you; it's not weaponized until people get their hands on it and grow it in a crop plot.
The first screenshot below shows Plant Species X in the wild. The next two screenshots show the bushes from which I've had random seed drops. Please note that I have found only one seed so far per bush type in all my searching. So it may not be a viable method of harvesting. Also keep in mind that, so far, I've managed to get between 7 & 12 seeds per harvested wild Plant Species X.
Growing and maintaining Plant Species X is actually quite simple if you have the farming skills. First, you need to know that Plant Species X requires a large crop plot. It won't fit in anything smaller. Secondly, the plot must be irrigated and fertilized. If you don't want to irrigate it, you will have to manually water it.
Once Plant Species X is fully grown it still requires fertilizer, but no longer seems to use water. It doesn't use a lot of fertilizer, but if you run out of fertilizer it may stop functioning as a defensive structure and may die.
Plant Species X has various settings like a turret once fully grown. Make sure you have it setup the way you want it and that you have not put it to sleep. As a matter of personal preference I keep mine set to Long Range and All Targets. That keeps the wild Dinos away too and helps prevent traffic problems around my bases.
One of the easiest and perhaps safest and fastest ways to get your hands on Plant Species X is with Dino Power. A minimum Dino for this would be the Trike, though a Stego or bigger would definitely be advisable.
The trick here is that Dinos have a much better chance of getting seeds than you do by hand, except in the case of harvesting an actual Wild Plant Species X. The two screenshots below show an area with the right type of swamp bushes just inside the edge of the swamp on the East Coast of the Ark. A good berry harvesting Dino can pull in Plant Species X seeds fairly quickly. This is in the area of GPS 56.3 - 83.3.
In the screenshots I'm using a Stego. It seemed more fitting to show you with an easier tame that people can get their hands on earlier in the game. And actually, when it comes down to seeds, I find it's all in the tail. How big is it? How much area does it cover in one swipe? And how good is the Melee damage on that Dino?
There are at least two Wild Plant Species X around a small pond at 53.7 - 81.1.
There is a single Wild Plant Species X at 52.1 - 81.5.
You can find a Wild Plant Species X at 59.7 - 63.9.
There is another Wild Plant Species X at 69.3 - 63.4.