Professor Jodie Holt from the University of California UC Riverside was the consultant botanist on Avatar. In this video, she gives a lecture to middle school children on the plants in the film and where the real world inspiration for them came from – she has lots of interesting examples from the film which could easily be translated to plant science teaching, and outreach projects. This is quite a long video, but it is fascinating. The Avatar stuff starts at about 15 minutes in, and Jodie takes questions from the children from 36 minutes onwards.
If the video is not working, go to YouTube: http://www.youtube.com/watch?v=J-l9fuumJ8w