From the Introduction: "This field guide includes nearly 90% of the trees and liana species of the rain forests of the low and medium elevations of the Western Ghats, India. Its chief aim is to provide a key for the identification of sterile specimens. However, it can also be used for other purposes. For example, the illustrations may be used in studies on the evolution of leaf architecture as well as in the identification of fossil leaf remains and impressions.
"This field guide begins with a key to the 5 major groups (A,B,C,D,E). These groups are further split into 32 elementary keys. The keys are unequal containing 3 to 60 species. They include species which share obvious similarities. However, the deeper we go into the subdivision of a given group, the less obvious become the distinctive characters; the last keys for each group contain those species without any common characteristics. At this level their separation is naturally much more difficult. Species with overlapping vegetative characters are separated in foot notes by using reproductive characters.
"Finally, the species lying close to each other in this artificial key may also point out some special phenomena such as convergence in vegetative characters."