Cornell University

Phylloporus, a gilled bolete

During most of my few mushroom hunting experiences I would regularly find huge amounts of two or three familiar mushroom species, and I would less frequently discover a beautiful new specimen that I had never seen before. Our visit to Cornell’s Ringwood-Lloyd Preserve on September 20th was no exception. In the middle of that dry week my chances of finding any interesting mushrooms were low. After spending most of the time complaining that the mushroom population of Ringwood was lacking in diversity, I saw something poking out of some thick leaf litter. I cleared away the debris and found a beautiful mushroom, far superior to anything else I had seen that day–it was tough, with a thick stem and a strong cap. The brown velvety cap had a few small raised spots on the surface of darker and lighter shades. The golden gills were strongly decurrent and faded to an interesting rusty brown reticulate pattern on the stem. Needless to say I was more than excited to take it to the lab and identify it.

Phylloporus rhodoxanthusUsing a couple of different keys, I decided that this specimen was Phylloporus rhodoxanthus, a member of the order Boletales. Members of the genus Phylloporus are ‘gilled boletes’. They belong to the order Boletales, as opposed to the gilled mushrooms traditionally placed in the order Agaricales. Instead of gills, boletes typically have a spongy hymenophore composed of vertical tubes that create a pored undersurface. Despite Phylloporus‘ gills, it is also grouped with the Boletales. Clues to this unexpected affinity lie in their fleshy texture and the fact that the gills can be readily pulled away from the cap, as can the pore surface of boletes.

Recent advances in molecular systematics are forcing taxonomists to make major revisions in the way mushrooms are categorized. Analyses of mushroom genes reveal surprising evolutionary links among groups previously thought to be distantly related. The Boletoid evolutionary clade is well known for diversity in morphological features ranging from the gilled forms to the pored ones and some even more distinctly different mushrooms. Recently, based on these molecular techniques, earthballs–which resemble tough-skinned puffballs– have been revealed as members of the Boletales (other puffballs are more closely related to the Agaricales). Mycologists have typically based fungal taxonomy on macroscopic characteristics; these discoveries are now causing radical changes to mushroom classification.

Phylloporus species were once thought to represent an evolutionary link between the gilled Agarics and pored Boletes. Boletes with large angular pores were once thought to represent the next step in bolete evolution. However, molecular data suggest that Phylloporus species arose from within a group of hum drum boletes with pores. So it seems that Phylloporus gills are convergent–a later reinvention of the gilled form of the agarics. Interesting and possibly unanswerable questions are why and how have these traits evolved?

Mushroom taxonomy has changed quite a lot over the years. First distinctions were made based on macroscopic features. The fathers of modern mycology, Carolus Linnaeus, Elias Fries, and Christian H. Persoon did not use microscopes much in developing their seminal mushroom classification schemes. Later, in the nineteenth and twentieth centuries, many scientists began examining mushrooms under microscopes of increasingly better quality, and classifications began to change. In 1947 this led Alexander H. Smith to separate the 232 species of Mycena mushrooms into subgenera based on microscopic features like spore shape. The most recent change in how mushrooms are classified came with the advent of molecular phylogenetic techniques based on DNA analysis. These new approaches have shed light on many mysteries of the evolution of mushrooms, and will prove to be instrumental in revising mycological systematics and the taxonomy of the thousands of mushroom species growing around the world.

Photo by K.T. Hodge. We thank Dr. Manfred Binder, who kindly corrected the identification of this mushroom, which we originally gave as Paxillus filamentosus, a different gilled bolete.



2 Responses to “ Phylloporus, a gilled bolete ”


Most people don't pay much attention to fungi, which include things like mushrooms, molds, yeasts, and mildews. Here at Cornell we think they're pretty fascinating. In fact, even the most disgusting foot diseases and moldy strawberries are dear to our hearts. We'd like to talk to you about fungi, so that like us, you too can tell gross stories at the dinner table. Afterwards, maybe you'll notice some things you would have overlooked before, and we think this could be good for the planet.

Kathie T. Hodge, Editor

Beneath Notice, our book of borescopic mycology.


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