The land of Airithrin is a horrible place, a land of reeking fumes and geysers of flame, lakes of lava and the strange life forms that emerge when elementals breed with mundane creatures
The flower commonly known as "Blood Petal," Haemorosa is a member of the Necrofoenae family - a family of plants that exhibit a disturbing affinity for the dead.
-Court Herbologist Gertrard di Vini, from his tome "dyFoenis Terrae Modae" - On the Plants of New Terra
At that moment the drizzle eased, and Ledoik could see as plain as day a blight upon the fields near the edge of the forest. Like a rock dropped into a pond, a wave of lighter shades of green emanated from the blights centre. Growing from the forest, where it was darkest, the field got lighter and lighter the further away it was from the blight. It was clear enough. The commander barked words, organising the archers, the few catapults they had and the giant rockslings to this side of the battlements. He motioned them to aim towards the blight, the dark patch near the fields edge
Regional insult for someone considered stubborn, or gullible.
You find a patch of edible funghi. They taste well and all, no ill effects. UNLESS you consume some beverage, even 3 (three) days after eating it. Then you become really sick with pains, vomiting, all the fancy stuff. As a gift or good meal, it could be a cruel joke or to make sure the heroes spend their time focused on the mission. And the fine soup you had in the inn yesterday could have some in.
(Inspired through a real-world fungus. Was really used to cure alcoholism.)