Thorns on roses are sharp, pointed structures that grow along the stems of the rose plant. They serve as a natural defense mechanism, helping to protect the plant from herbivores and other threats. Thorns can vary in size and shape, depending on the specific variety of rose. While thorns can be seen as a nuisance for gardeners and flower enthusiasts, they play an important role in the plant's survival. The presence of thorns can deter animals from eating the roses, allowing the plant to thrive and produce beautiful blooms.