Adder’s Tongue
Adder’s Tougue is a herb that requires a herbalist to be level 400 to collect and can only be found at Sholazar Basin. It is the least common herb within the Northrend zone, but it can be found everywhere in Sholazar Basin which makes up for it.
So without a doubt, head to Sholazar Basin to farm Adder’s Tongue and see maps below for the routes.