You cause three, 10-foot squares on flat surfaces within range to be covered in toxic mushrooms. When a creature enters or moves within a square’s space, the mushrooms burst, releasing a cloud of spores in a 5-foot radius sphere around the square, and ending the spell’s effect in that area. Each creature caught in the cloud must make a Constitution saving throw or take 2d8 necrotic damage, 2d8 poison damage, and be poisoned until the start of your next turn. On a successful save, a creature takes half as much damage and is not poisoned.   If a square appears on substantial plant matter (such as in a forest or overgrown field) or is in darkness, it is invisible unless a creature succeeds on an Intelligence (Investigation) ability check against your spell save DC, or its passive Intelligence (Investigation) is higher than your spell save DC. It has advantage on this check if it saw you cast the spell.