Bracket Fungi Appendix
(Basidiomycota - Hymenomycetes)
In Bracket Fungi the spores are produced inside tubes that line the underside of the fruitbody. These tubes open by pores to the exterior giving a perforated appearance to the under surface. For this reason, species in this group are sometimes called Polypores. Tubes may be shallow or more than a centimetre deep. Pores are often circular in face view but may be angular, irregular or even labyrinthiform (= maze-like). In a few cases the walls between pores may break down radially to give a gill-like appearance to the underside of the fruitbody as in Lenzites or in older specimens of Daedaleopsis confragosa. Pores can be almost a centimetre across or so narrow that, as in Ganoderma applanata, they are difficult to see without a magnifying glass. Deeper tubes and a smaller pore size both serve to increase the spore-producing surface (hymenium).
For the most part, fruitbodies of bracket fungi are tough and leathery or woody in texture. Inside there are thin-walled, living hyphae for transport of nutrients and production of spores. As well, most bracket fungi contain thick-walled, dead hyphae. These thick-walled, branching fibres interlock and form an extremely hard and rigid fruitbody which can persist for long periods and sometimes many years. The hardness of the fruitbody will be related to the proportion of these thick-walled cells.
Bracket fungi are so-called because they grow from the sides of trees like shelves. Some are large and robust whilst others are thin and delicate. A few polypores do not form brackets and are mushroom-like, with a cap and a central stalk. At first glance, they look like boletes, but their tough, leathery texture gives them away. Also, in some polypores shelves are lacking and fruitbodies form of a flat layer (resupinate) on the undersurface of a twig or branch.
Most mushrooms turn into a putrifying mass within days. Bracket fungi, however, can last from weeks to months or even overwinter. A few, Ganoderma applanata (artists conk), can persist for many years, producing a new layer of pores on the underside each year. During the summer heat or drought, brackets may shrivel a bit but can recover in rainy periods to resume spore production.
Bracket fungi are not the most attractive fungi and tend to be drab and uninteresting. There are exceptions to any rule, however, and there are several colourful bracket fungi. Chicken of the Woods (Laetiporus sulphureus) is rich yellow to orange-yellow with reddish tints. Pycnoporus cinnabarinus is orange to faded orange on the upper surface and brilliant cinnabar underneath. Turkey Tail (Trametes versicolor) has attractive zonation ranging from tans to rich browns in a velvety textured surface. Honey-coloured resin droplets exude from the edge of Ischnoderma resinosa to attract the eye and Fomitopsis pinicola has a colourful orange-brown band lining the edge.
Bracket fungi are wood rotters par excellence and, like many other fungi, play a vital role in the Carbon Cycle in processing woody debris. It is common, therefore, to find bracket fungi fruiting on logs, stumps, branches, or twigs. Some bracket fungi are parasites and grow on living trees. A few, such as the Rooted Polypore (Polyporus radicatus) colonize buried wood and produce stalked fruitbodies seemingly directly from the ground.
Because of their tough, woody consistency, bracket fungi are not highly regarded as edibles. Nevertheless, a few have made the gourmet's list. Amongst these is Laetiporus sulphureus sometimes called "Chicken of the Woods." The young edges of the expanding brackets are reported to be edible and very good but this high opinion is by no means unanimous.
There are some bracket-like fungi that have no pores. The underside may be uneven but is more or less smooth. These are called stereoid fungi. Sometimes they look like paint on wood. Or they form shelving brackets and mimic the true bracket fungi. Stereum ostrea is called False Turkey Tail because of its superficial resemblance to Trametes versicolor (Turkey Tail). They are easily distinguished by looking underneath. The true Turkey Tail has pores and the False Turkey tail has none.