The plant is poisonous to the touch, with its poison gradually turning affected animals’ bones into spiders. Once the spiders escape, they burrow into the ground, where new plants sprout.
A specimen of an otherwise mundane species of plant, except that it was found growing on the moon’s surface. Also, its seeds are made of some unknown element with an atomic mass of 666.
Digital analysis reveals that there is actually no plant in this image, the perception of it is entirely memetic, and also triggers a secondary effect: a tall humanoid figure covered in eyes that is now going to appear in your dreams.
Some possibilities: