As a green card holder do you need a passport to travel to the usa without a Jamaican passport?
If you are a legal permanent resident of the US ("greencard holder") and wish to travel to Puerto Rico, you must carry the greencard in order to board the return flight from PR to the mainland US. A passport is not necessary. A greencard is not required to enter PR, but is required to return to the mainland US. Immigration officials check for the greencard before you are allowed on the plane for the return flight. There is no need to carry a passport. Some people suggest that a driver's license is all that you need - not true for permanent residents. Take your greencard!