MonoGrass

The table below shows ONLY 
* FIRST instance of static encounter OR FIRST instance of wild encounter and 
* FIRST instance of wild encounter or SECOND instance of static encounter if an earlier static encounter of that same species is either time-limited or contains multiple mutually exclusive species. 
For example, Bulbasaur is listed twice because it can be obtained through starter choice, which is an instance of static encounter that contains multiple mutually exclusive species, and also through wild encounter.
Some Pokemon included here may not have the type suitable for the mono run, but evolves into Pokemon that do, or have other forms that do, or may qualify due to the lack of Pokemon in early game.
For the full range of all possible locations, check Pokedex.