In the leaf,vascular bundles are found in the

In $Acacia$ species,the first few leaves are pinnately compound. Then there are leaves with flattened petiole and fewer pinnae. The leaves of the adult plant have parallel-veined flattened petioles and no pinnae. It shows that:

Environmental heterophylly with respect to habitat is seen in-

Which of the following statements is incorrect regarding a leaf?

Petiole is winged in

In $Lathyrus$ $aphaca$,the leaves are modified into