Having spoken to the ruler of the Oakmyst dryads, Empress Anassa, and I have learned that there is a corrupted evil plant known as Rotweed behind much of this woodlands tainting. I am headed to Teardrop Cave in Oakmyst where they say this being lurks. Should I need to return to Oakmyst Forest, I may do so via any mariner bell within the City of Qeynos.