Cerebral peduncle:

this image shows an isolated brainstem (and the thalamus, which is the pink structure at the top of the brainstem). One of the cerebral peduncles is colored green and indicated with an arrow.

a large bundle of neurons that resembles a large stalk (the Latin pedunculus means "footstalk") and stretches from the cerebrum to the pons. There are two cerebral peduncles, one on each side of the brainstem. Definitions of what is included in the cerebral peduncles vary slightly, but a common definition is that they consist of the entire portion of the midbrain that lies anterior to the cerebral aqueduct. The cerebral peduncles contain important descending tracts like the corticospinal tract and corticobulbar tracts.