How does a plant called an exotic, a ‘naturalised’ and a native?

 
 
I am very interested in understanding how one decides and traces the nativity of a plant. How is it that a plant gets its identity as a exotic, a ‘naturalised’ and a native?

Is such information available in books?
Even if it is available, I feel this would be an interesting topic for all the experts to discuss on eflora based on their experiences and their understanding about the topic.
Please let me know what you think.

Please peruse the attached paper. That will help…
Attachments (1)- Alien plants in checklists and floras.pdf (2 MB)

Thank you very much … The paper is very informative and helpful.

See one more attached paper. Attachments (1)- Alien Flora India_Khuroo et al_2012.pdf

very nice details
took a lot of painstaking data mining and searching

Thank you very much … The second one is highly helpful!

Very nice papers, highly useful