Geopyxis carbonaria is a species of fungus in the genus Geopyxis, family Pyronemataceae. First described to science in 1805, and given its current name in 1889, the species is commonly known as the charcoal loving elf-cup, dwarf acorn cup, stalked bonfire cup, or pixie cup. The small, goblet-shaped fruitbodies of the fungus are reddish-brown with a whitish fringe and measure up to across. They have a short, tapered stalk. Fruitbodies are commonly found on soil where brush has recently been burned, sometimes in great numbers. The fungus is distributed throughout many temperate regions of the Northern Hemisphere. It is found in Europe, Turkey, and North America. Although it is primarily a saprotrophic species, feeding on the decomposing organic matter remaining after a fire, it also forms biotrophic associations with the roots of Norway spruce.
