This link will pronounce the names of most botanicals so you can always sound like a pro, you can also save the *.wav file and create your own dictionary. You could also down load the files to an ipod and take it with you. It would also be very usful if you ever gave a tour of your local botanical garden. I think this is one of the best freebie I have seen on the web, enjoy.

Here is a link that might be useful: Pronouncing Botanical Latin: