Roselia is a small, green Pokémon with poisonous thorns on its head, and each of its hands bloom red and blue roses. Roselia also wields a single-leaf with yellow stripe running down it, covering the torso, thigh, and partially the legs.
One of May's contest rivals, Drew, owns a Roselia that seems to be his signature Pokémon. It is very elegant and is highly trained in contest combinations. It later evolved into Roserade while Drew was traveling in Johto.
* - This is the amount of points required to capture the Pokémon (excluding boss Pokémon). ** - This is the reaction of the Pokémon when players approach it.
Roselia could have simply been originated as a nymph, or a fairy. Even simpler, Roselia could have just been based on two roses. Though in actuality, there are no such things as blue roses. Although since before Pokémon Ruby and Sapphire's release, scientists were and are still working on making the Blue Girl Rose actually blue. In fact, some roses are actually blue, but they are genetically altered.
Roselia's name could have originated from the two words, "Rose" and "Azalea". The azaleas could have come from the fact that some azaleas are blue, referring to the left rose.