No doubt the best place in the whole of world of warcraft to farm Adder's Tongue is Sholazar basin compared to the other two locations Gundrak and Drak'Tharon Keep this location is 100 times better and offers more rewards and many other different herbs.
To be able to farm for Adder's Tongue you will need a farming skill of 400 and farming this herb gives you a chance to loot Crystallized Life and Frost Lotus,
Adder's Tongue is Farmed mainly to level professions and to sell as the price for this herb isn't not the best. It is mainly used in Alchemy and Inscription.
Take a look at the Rote below and let us know if you like it.