What is the ruling on picking flowers and fruits from public streets, and picking basil from the university courtyard?

As for trees in public places, which are not owned by anyone, it is permissible to pick their fruits and flowers. If they are maintained by the responsible authorities, then it is permissible to eat from their fruits without taking anything away, unless it is known that the authority does not prevent it. Picking flowers is not included in the concession granted for eating, due to the lack of an apparent benefit, and the authority's intention might be for the flowers to remain for ornamentation.