Planted
Planted is the past tense of plant.
In the past a "stick" was part of a plant and this "stick" was "stuck" onto the plant.
The past participle is planted.
The past tense is planted.
The simple past tense and past participle forms are both planted.
Coal is evidence of past plant life.
"The plant was growing in the sunlight."
Plant is a noun, so it is all the same word.
diverse
You add -ed because plant is a regular verb. -ed is added to all regular verbs to form the past tense.
A paleobotanist studies ancient plants and plant fossils to understand the evolution, diversity, and ecology of plant life in the past. They use these fossilized remains to reconstruct past environments and ecosystems.
It is a fossil.