There's mandragora on the mountains, but as far as I know it's impossible to collect. Last time I saw it was on the futa elfs forest, but as I have reached master level at gardening, from time to time I get one when I worked on my field. I don't remember the exact version, but on one of the earlier versions, going to the back of Sebastian's home (out) and pressing enter, you go to a forest where the slave girl (or princess) Jasmine can increase your gardening level, then you save the file and use it on the new version.