(16) The term "marihuana" means all parts of the
plant Cannabis sativa L., whether growing or not; the seeds thereof; the resin extracted from any part of
such plant; and every compound, manufacture, salt, derivative, mixture, or preparation of
such plant, its seeds or resin. Such term does not include the mature stalks of
such plant, fiber produced from such stalks, oil or cake made from the seeds of
such plant, any other compound, manufacture, salt, derivative, mixture, or preparation of such mature stalks (except the resin extracted therefrom), fiber, oil, or cake, or the sterilized seed of
such plant which is incapable of germination.