How are leaves categorized?

Leaves are categorized primarily by their arrangement and margin because these characteristics provide significant insight into the plant's classification and adaptations. The arrangement refers to how leaves are positioned on a stem—such as alternate, opposite, or whorled—which can indicate different evolutionary adaptations. The margin of the leaves, which refers to the edge of the leaf, can be smooth, serrated, or lobed. These features are essential for plant identification and contribute to understanding their function in environmental adaptation and water retention strategies.

While color, size, shape, and photosynthetic capabilities can describe leaves, these attributes are not the primary focus for systematic classification. Color can vary widely even within the same species, size and shape may not provide consistent classification across different species, and photosynthetic capabilities are generally more related to internal processes rather than external morphological characteristics that define plant types. Thus, the arrangement and margin of leaves serve as more reliable and informative criteria in the context of plant biology and taxonomy.