Mirage Mounds

Mirage Mounds are small cactus-like plants the live in deserts and other arid environments. They are particularly powerful magical components, and can be used for a variety of magical and alchemical creations.
However, they are extremely frustrating to harvest, as they have the ability to case their own image to other locations near itself, as well as blend itself in to the surrounding environment. Thus, many have tried and failed to locate the plants' actual location. Those who succeed though can often sell them for high prices to any magical adept.
Enchanters and smiths particularly covet these plants, as their ashes when mixed into a molten metal, will imbue it with magical properties, and make it particularly good material for enchanting.
Some have even learned to brew potions with it, that are supposed to make the consumer invisible for a time.

If used to brew a potion, potion gains the benefit of invisibility. Makes the drinker gain the effects of the invisibility spell for 1d4 hours.