A complete botany guide to Khao Yai is available for download for free from DNP ( Department of national parks) website. It s a massive 262 pages e-book co-published with Christian Puff from the Faculty of Botany in Vienna. This e-book is highly instructive, cover amazing species and is illustrated with a lot of photographic plates. A must see before heading to the park. (In Thai and English.)
Click Here to download the complete guide of Khao Yai plants from National Park Department website. ( pdf file- 120Mo)
Or check the website page where you can download it ( then check the e-book links at the bottom of the left column)
Check Christian Puff homepage with more plates from Khao Yai and other parks in Thailand.