Question

Why do rose stem has thorn

Answer 1

Thorns usually can't be broken off easily. ... Some scientists speculate that roses might have thorns to protect them from being eaten by animals attracted by their wonderful smell. Not all roses have thorns, though. Most do, but there are a very few varieties of completely thornlessroses.

HOPE IT HELPS

Answer 2

To protect against from the animals by eaten and attracted from their smell