I'm always on the hunt for books on cacti, in particular ones with illustrations rather than photos.
I'm going to post some of the nice illustrations I find on the net in this thread, I encourage others (EG I know you've got to have some stuff like this) to do the same.
Probably a good idea not to infringe copyright. here are a lot of older books uploaded as PDFs to legit sites out there.
These are from the Missouri Botanical Garden
http://www.illustrat...ooks/browse.asp
© 1995-2012 Missouri Botanical Garden
http://www.illustratedgarden.org