Artist’s Conk

Ganoderma applanatum
Tuesday, July 26, 2011

           These huge conks (a term for any large bracket or shelf fungi) range from 5-75 cm (2-30 in) in diameter and can approach 10 cm (4 in) in thickness. They are generally fan-shaped or semicircular, although some specimens may be irregular. The upper surface of the conk is a dull brown to grey-brown, and is usually zonate (having belts or stripes) and furrowed or lumpy. The lower surface of the conk is white in color. It is composed of densely packed, circular, spore-producing pores (4-6 per mm). A new layer of pores grows with each new year; thus, it is possible to age one of these conks by slicing it open to count the layers of old pores. This fungus is a perennial, and specimens have been known to live for dozens of years. One interesting feature of this fungus is the fleshy white lower surface: it bruises to a dark brown when damaged. Thus it is possible for artists to create intricate designs on the undersides of these shelf fungi. As the picked fungus ages, however, those designs become permanent and it is impossible to create new ones. These woody fungi and their works of art may remain intact for years if stored indoors. The white, bottom surface is also commonly painted on, earning its common name of “artist’s conk.”

           These conks are polypores, a classification which literally means “many pores.” Most polypores, including G. applanatum, are woody and inedible.  G. applanatum can, however, be made into a tea with medicinal properties. These conks, like many other polypores (and fungi in general), are saprobic, meaning that they attain energy from decomposing organic matter. Some G. applanatum, however, are parasitic and will attach themselves to injured trees and slowly suck the energy from them, eventually killing them. They are typically found on rotting logs, stumps, or upright trees and may occur solitarily or in clusters.

           These impressive shelf fungi are members of an extremely common and widespread species. Artist’s Conks can be found in every state and, indeed, across most of North America. Although similar species do exist, G. applanatum cannot be rivaled in terms of sheer size and prevalence across a wide range. Several characteristics that make the Artist’s Conk unique include relatively small spores (when viewed under a microscope), a dull, furrowed upper surface, and its great thickness.

           These two fungi were collected by the Biology of Fungi Class in the Mount Rogers area. They also occur near the station. Although neither of these two have had a section cut out of them, it is likely that they are many years old, judging by their great size and thickness.

Hazel Galloway

See images of artwork done on fresh Ganoderma here, courtesy of Marie Heerken.