Ok I am going to make a statement that I know isn't true so you guys can challenge it!
All of the known synonyms should now be listed on the site! You can search or paruse the list here:
http://www.cactiguide.com/namesearch/
(Let me know which ones I missed! )
Calling all synonyms...
Calling all synonyms...
All Cacti are succulents, but not all succulents are Cacti