What type of modified structure are spines classified as?

Spines are classified as modified leaves or stipules because of their structure and origin. In many plants, spines develop from leaves that have adapted to reduce water loss and deter herbivores. Instead of performing photosynthesis as typical leaves do, these modified leaves are transformed into hard, sharp structures primarily for protection. This adaptation is particularly common in arid environments where conserving water while deterring potential threats is crucial for survival.

Understanding that spines originate from leaves rather than roots, stems, or leaf nodes is essential for recognizing how various plant structures serve specific functions within the context of ecological adaptation. This classification helps in the broader study of plant morphology and adaptations found in diverse environments.