"Many strange things may be seen in the Great Swamps, not all real. But I tell you, there was a ship and it was real! Well it was old and all sails torn and had many holes in the hull... but anyway it was hundreds of miles from the Sea! How it came to be there, I can only wonder..."
(If it is not a hallucination, may be inhabited by wererats.)
Certain trees have sap that is filled with magical potential. Their sap is harvested and distilled down to produce various types of potions, much like maple syrup is collected in some areas. The magical effects of these syrupy potions are often fairly trivial; perhaps they simply cause the imbiber to grow hair more quickly, summon butterflies, or walk a few inches above the floor. People enjoy the syrup as a flavoring, instead of imbibing it for its magical powers.