This has been puzzling me for a bit, I'll say this right now - this is mainly about the American English names in the Pokémon anime series. This does not include the names of locations or pokémon. Here's what I have so far:
Misty - references the mistflower
May - references the mayflower
Dahlia (Ketchum), Ash's mom
Jasmine, a Steel-type Gym leader (the mine in her name reflects this)
Cilan - from cilantro
Cress - from both watercress and graden-cress
Chili - like the chili pepper
Erica - a Grass-type Gym leader
Gardenia, not sure
Ash (Ketchum) - the ash tress: mostly likely the red ash, the blue ash, the green ash, and the yellow ash
Samuel "Sammy" Oak, a Pokémon professor - references the Salem Oak
Gary Oak, a new/novice Pokémon professor - references the garry oak
Elm, a Pokémon professor
Birch, a Pokémon professor
Juniper, a Pokémon professor
Gardenia, a Grass-type Gym leader
If you know a minor character (character of the day, please list the American episode name/number), a secondary character (link an image of him/her), or even a major character - any one whose name references a plant of some sort.
Do you have any suggestions?
Edit: This is mostly for the regions of Kantō, Jōto, Hōen, Rōta, and Sinnō. Unova/Isshu and the other regions may be ignored or listed separately.