Please note that Mommsen uses the AUC chronology (Ab Urbe Condita), i.e. from the founding of the City of Rome. You can use this reference table to have the B.C. dates
The culture of the olive was of later introduction, and certainly
was first brought to Italy by the Greeks.(10)
10. -Oleum- and -oliva- are derived from ἔλαιον, ἐλαία,
and -amurca- (oil-less) from ἀμόργη.
The olive is said to
have been first planted on the shores of the western Mediterranean
towards the close of the second century of the city; and this view
accords with the fact that the olive-branch and the olive occupy
in the Roman ritual a place very subordinate to the juice of the
vine.
The esteem in which both noble trees were held by the Romans
is shown by the vine and the olive-tree which were planted in the
middle of the Forum, not far from the Curtian lake.