|Major Groups > Cup Fungi / Crust Fungi > Aleurodiscus oakesii
by Michael Kuo
If your vision is as bad as mine, it's easier to see Aleurodiscus oakesii, which measures only a few millimeters across, from 20 feet away; it creates smooth patches in the bark of hardwood trees--especially the bark of oaks. In fact, when I wrote this site's page for white oak three years ago, I provided a description and illustration of such a smooth patch, not knowing that the cause was a mushroom!
Up close and personal, Aleurodiscus oakesii requires removing one's glasses (for me, anyway) and pressing one's forehead against the tree to inspect the patches of smooth bark. The tiny, saucer-shaped mushrooms are pale brown, and often appear near the borders of the smooth patches. They are so tiny that there is almost nothing to describe--unless you use a microscope to see the many fascinating and beautiful microscopic features (see the description below).
While Aleurodiscus oakesii is a parasite, it sticks to the outer bark of the trees it infests, and does not seriously threaten the health of its hosts.
Ecology: Parasitic; growing alone or, more commonly, gregariously on the outer bark of hardwoods--especially oaks, elms, and hop hornbeam; appearing year-round, when weather is warm; widely distributed in eastern North America.
Fruiting Body: Only a few millimeters across (to about 5 mm maximum); saucer-shaped or irregular; broadly but centrally attached to the bark; leathery; upper surface pale brown and fairly smooth; under surface whitish and minutely fuzzy; the margin often folded slightly upwards to expose the under surface; without a stem.
Microscopic Features: Spores 17-25 x 12-14 µ; elliptical or egg-shaped; roughened at maturity; amyloid. Acanthohyphidia present, developing prominent and numerous spines. Pseudocystidia present.
This site contains no information about the edibility or toxicity of mushrooms.
Cite this page as:
Kuo, M. (2006, May). Aleurodiscus oakesii. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/aleurodiscus_oakesii.html.