What is Heterophylly ? Give its types



The occurrence of more than one type of leaves on the same plant is called heterophylly. It is of three types:
1.Developmental heterospory : Leaves of different • forms and shapes arise at different times during the growth of the same plant, e.g., Brassica campestris (Mustard), Sonchus, Eucalyptus.
2. Habitual heterophylly : Leaves with different shapes and incisions arise on the plant as if the Hemiphragma heterophylly (East Indian herb), the main stem bears ovate and entire leaves, while the branches have acicular leaves.
3. Environmental heterophylly : It is found in some aquatic plants, where aerial and floating leaves differ from the submerged leaves. The aerial and floating leaves are generally broad and usually unlobed while submerged leaves are ribbon shaped, linear and are very much dissected, e.g., Rannunculus, Aquatilis, Limnophylla heterophylly