According to Genesis, the dove returned to Noah carrying a freshly plucked olive leaf.
Genesis 8:11 says the dove came back in the evening with an olive leaf in its beak. Noah understood this as evidence that the waters had receded from the earth enough for vegetation to appear or be reachable.
The detail became one of the best-known symbols associated with peace, hope, and the end of catastrophe. In the biblical sequence, however, it is first a practical sign in Noah’s search for dry land. The dove had previously returned without such evidence and later did not return.
The story says “olive leaf,” not a generic green branch. Artistic depictions often enlarge the leaf into a prominent branch, but the specific object named in Genesis is a freshly plucked olive leaf.