Amazon.com: http://xrl.us/BestOrchidBooks
Any other recommendations?
A problem with the three or four most thorough orchid
'encyclopedia'-type books is that they all have significant and critical
errors and misinformation.
There are a few on particular genera or types which are valuable, The
genus Cypripedium, the Hillerman Angraecum books, etc. You get the
point. Most 'general' orchid books are just that, and it limits their
usefulness and veracity. The more specific ones are often good, but then
you need to start collecting all 40, 50, or 200 of them!