In $Opuntia$ (prickly pear),the spines are modified forms of:

In some plants like Cotton and Eucalyptus,leaves change their shape. This phenomenon is known as heterophylly and it helps to determine the:

Leaves arising from an underground stem like a bulb are called radical leaves. The leaves that arise on the nodes of stem branches are called:

Whorled simple leaves with reticulate venation are found in ...........

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:

When the apex is pointed,hard and sharp like a spine as in Date Palm,it is called