
There are books that may be useful have the call number 580 to 589. More on herbal and alternative medicines are found in 615.3 to 615.5 and have been pulled for you.
Medicinal Plant Links to get you started:
http://www.hort.purdue.edu/newcrop/med-aro/toc.html
http://world.std.com/~krahe/html1.html
http://www.magdalin.com/herbs/
http://www.scs.leeds.ac.uk/pfaf/index.html
http://www.nps.gov/plants/medicinal/plants.htm