The plant realm is a verse that exists in the middle of the 1st iteration local Transcendent Omniverse. There is only ONE of these in the entire everything. It's filled with, you guessed it, plants. It's an endless plane of soil with occasional big forests of lots of plants. The reason there is only occasional forests of the plants is because the verse is infinite. One half of the verse is the soil, and the other half is the plants and air. There is also other things weird in this verse.
1. The place never has wildfires and the plants never need wildfires.
2. Every exactly 24 Earth hours, it rains for exactly 3 minutes.
3. Every exactly 720 Earth hours, the 1st seed of a new species of plants here is created.
4. It's always sunny here other than the times it rains despite not having a sun.
5. Any oxygen molecules within a range of exactly half a meter for exactly 10 seconds will for some reason become carbon dioxide. This happens so the plants have carbon dioxide they can use for food.