Bel laughs. Because he wasn't sure how well that would go over, and it seems to have gone over well. He keeps his arm in a position that makes it comfortable for Barcus to hold it.

"Don't forget fungus, dietary staple of the Underdark. It could be that this," he waves with his free hand, "is the easy sell. Not even the edible plants, but the pretty ones. I've even know a drow or two to keep surface plants for decoration, though mostly to show off how much magic could be spared to keep one alive."