The multicostate parallel venation takes place inside_____.

The multicostate parallel venation takes place inside grasses and palms.

Veins are the organization of leaf blade veins and capillaries is called veins. There are two main types of veins-reticular and parallel veins. In reticular veins, veins and capillaries combine to form a reticular tissue or network. In parallel veins, veins and capillaries are placed parallel to each other.

There are two types of parallel venation - unicostate and multicostate.
A unicostate or pinnate type parallel venation is the one in which the leaf has only one major vein or midrib, for example, banana and canna leaves.
A multicostate or palmate type parallel venation is the one in which the leaf has multiple major veins or ribs arising from the bottom of the leaf till apex, for example, grasses and palm leaves.