(N/A) Heterophylly is a phenomenon in plants where the leaves on the same plant exhibit different shapes and sizes at different stages of development or in response to different environmental conditions.
$(1)$ Developmental Heterophylly: In some plants,the juvenile leaves are different in shape from the mature leaves. For example,in $Larkspur$ (Delphinium),the juvenile leaves are simple,while the mature leaves are more complex and lobed.
$(2)$ Environmental Heterophylly: This occurs when the environment influences the leaf shape. $A$ classic example is $Buttercup$ (Ranunculus sceleratus),which grows in both terrestrial and aquatic habitats. The leaves produced in the air (terrestrial) are broad,while those produced in water (aquatic) are finely dissected and thread-like. This is an example of plasticity,where the plant's phenotype changes in response to its environment.