In some xerophytes, such as cacti, most of the leaves are modified into spines, greatly reducing the leaf area for transpiration; the photosynthetic function of the leaves is taken over by the green stems.

• 在一些旱生植物中，如仙人掌，大部分的叶片都特化为刺，极大的减少了叶片区域的蒸发作用，同时光合作用为绿色的茎所承担。