Dictionary of Tamil Plants and trees:

These two books contain Tamil names and botanical names. You won’t find “Tamil Names with Tamil script” (that is available with these two books) even on the  internet up to what I have searched in Google.
It’s a rare book and I found no errors in it, up to my knowledge.
Also, it’s not only just  a simple Dictionary but also a compilation of a lot of dictionaries referring to a lot of books and other dictionaries .
The author has quoted very interestingly in the introduction:
  1 the worst criminals should neither be executed nor sentenced to forced labour, but should be condemned to compile dictionaries, because all the tortures are included in this work’’. Manual of Lexicography, Ladislav Zgusta, page 15, Mouton, Paris, 1971.

We have to thank the the authors and give credit to their work in future if we use it:

Part 1(225 MB):
Part 2(440 MB):