[...here I have 3 different miniature roses, planted together. One with red blooms, one with white and one with yellow. I wanted to add a picture to the Database but didn't know the scientific name for miniature roses? Can anyboody help me?]

They're all hybrids, so they don't have a species name. You can add them to this page:

Roses (Rosa)

I didn't know that, thank you! x