Added by Natura, Nether Glowshrooms are found in the Nether. They come in Green,Blue and Purple. And they resemble the standard Brown Mushroom except in coloration. Combining all three colors with a Wooden Bowl will craft Glowshroom Stew. They can be placed back down as long as the light level is 12 or less. They do not reproduce but can be turned into giant mushrooms using Bone Meal like regular Mushrooms.
Since Nether Glowshrooms act like regular minecraft mushrooms, you may use Bone Meal on them to create a large Nether Glowshrooms. The sizes produced are very similar to vanilla minecraft giant mushrooms and will require the same amount of space in order to grow them. If you want to have giant Nether Glowshrooms of multiple varieties next to each other, they cannot overlap at all with a 5 block separation between types.