Hierophant Thayreen at Amberpine Lodge wants you to go to Grizzlemaw and obtain 8 of Vordrassil's Seeds.
We cannot allow Vordrassil to grow again. If the furbolg regrew it once, they can do it again.
Go to Grizzlemaw, in central Grizzly Hills, and obtain Vordrassil's seeds. I will make sure they're properly disposed of.