The Movie: Ellie Sattler, a paleobotanist, examines the resurrected Mesozoic plant life displayed all over the park. She warns the other characters about the potentially harmful dino-flora, but nobody really hears her because who cares about plants when there are Rexes and raptors on the loose?
Real Life: Okay, so the dinosaurs were cloned from 66-million-year-old blood. But how the heck did the plants get to Jurassic Park? Xylem cloning? Whatever genetic wizardry went into bringing extinct plant life back into the modern age is never explained in the movie.