The thorns and tendrils of Bougainvillea and Cucurbita are the examples for 

Homology is a character shared between two or more species that was present in their common ancestor. Thorns of Bougainvillea and tendrils of Cucurbita arise from the axillary bud, but their functions are different. Thorns provide protection from predators and tendrils are useful for climbing, they homologous organs and show divergent evolution.