Blooms of a yellow roseA rose is a perennial flower shrub or vine of the genus Rosa, within the family Rosaceae, that contains over 100 species and comes in a variety of colors. The species form a group of erect shrubs, and climbing or trailing plants, with stems that are often armed with sharp prickles. It is a common error to refer to roses having thorns. But thorns are modified leaves, whereas these sharp protrusions on a rose are modified epidermal tissues (prickles).