Updated with my regional variant of Oddish, Gloom, Vileplume, and Bellossom.
They're based on a type of plant called Peperomia, which is like a succulent. They have tendril-like "flower spikes" that grow once in a while when the plant is especially thriving. I came up with this Pokemon line during the beginning of the pandemic when I was growing a lot of different Peperomia plants.
Oddish is based on the Peperomia Rosso:
Gloom is based on the Peperomia Caperata (Red Luna):
Vileplume is based on the Peperomia Argyreia (Watermelon):
And Bellossom isn't based on a specific Peperomia, but rather generic succulents with the Peperomia flower spikes.
Because of my inevitable overabundance of Grass-Type Pokemon, these are not Grass-Type at all. Oddish, Gloom, and Vileplume are Psychic/Poison, and Bellossom is Psychic/Fairy. Their flower spike tendrils are able to read emotions and energies in the air as well as sting and poison opponents like jellyfish tentacles.
These are some of my favorites of my regional variants. Peperomia are really cute plants, so it was great to be able to make Pokemon based off of them!