Phellinus robiniae, commonly known as the “Cracked Cap Polypore,” is a woody bracket fungus that is most easily identified by its habitat. This fungus grows almost exclusively on locust trees. In fact, the fungus is such a common pathogen of locusts that nearly every Black Locust tree has at least one P. robiniae mushroom on it. The mushroom is also distinguished by its furrowed cap – which gives the fungus its common name – and its dull brown pore surface.
fungal interactions with trees
Gymnosporangium juniperi-virginianae is a rust fungus known as Cedar-Apple Rust (sometimes abbreviated to CAR) that causes disease in Eastern Red Cedar and in apple trees. This fungus is unique among rusts because it produces large fruiting bodies. On cedar trees, the fruiting bodies resemble lumpy brown golf balls with long gelatinous orange tentacles bursting out of them. On apple trees, the disease causes more damage but produces only orangish spots. The complex life cycle of Cedar-Apple Rust means the fungus is easy to control, although these control methods resulted in a legal case that was argued before the Supreme Court of the United States!
Fungi appear in the news with surprising frequency. However, many of those stories do not provide any new information. Below is a summary of what we’ve learned about fungi from August through October 2017. Read below to learn about: ballistospory, chromosome evolution, fighting fungal pathogens (in humans, bats, and bananas), psilocybin, oil-eating fungi, and more! Visit the associated links to get the full story.
Boletinellus merulioides is an odd mushroom, both in appearance and ecology. The Ash Tree Bolete can be readily identified by its tube surface – which is only a few millimeters thick and looks more like a network of ridges – and by the fact that it fruits under only ash trees. B. merulioides appears under ash because it has a unique symbiotic relationship with a pest of ash trees: the Leafcurl Ash Aphid.
Coffee Rust, also known as Coffee Leaf Rust and in Spanish as “roya,” is a disease of coffee plants that is caused by the fungus Hemileia vastatrix.1–3 H. vastatrix is, as its common name implies, a member of the rusts (FFF#130). Unlike most rusts, however, it has a simple infect-sporulate life cycle, which is likely one reason the disease has been so successful.1 Coffee Rust is a particular problem in Central America, produces 15% of the world’s arabica coffee and exports roughly 432 million kilograms of coffee to the United States annually. The region suffered a devastating outbreak of the disease in the early 2010’s and has yet to fully recover.4–6
Sirex noctilio, known as the “Sirex woodwasp” or “European woodwasp” (sometimes spelled “wood wasp”), is an invasive species that attacks most species of pine trees. Interestingly, the insect is dependent upon the fungus Amylostereum aerolatum to complete its life cycle. The Sirex woodwasp carries the fungus with it to new trees and in return the fungus becomes a meal for the Sirex woodwasp’s larvae.
This emerging fungal disease of ash trees was first reported in 1992 in Poland. Over the past 24 years, Hymenoscyphus fraxineus has spread throughout Europe and (with the help of the invasive Emerald Ash Borer beetle) is now poised to eradicate ash trees from the entire continent.
Witches might not be real, but witches’ brooms certainly are – and they’re destroying chocolate! Yes, Halloween’s favorite treat (chocolate) is suffering at the hands of a disease with a Halloween-themed name: Witches’ Broom Disease. Witches’ brooms are actually fairly common and occur on many different plants. In chocolate trees (Cacao trees, Theobroma cacao, whose genus name literally means “food of the gods”), witches’ brooms are caused by the fungal pathogen Moniliophthora perniciosa and have an enormous economic impact on chocolate production in Central and South America.
The banana that you know and love may soon be a thing of the past. I know, you probably think that I’m exaggerating the threat to this ubiquitous crop, but the possibility of bananas disappearing from grocery shelves forever is very real. In fact, it nearly happened once before. Here is a brief history of the modern banana: in the 1950’s, bananas were wiped out by a disease called Panama Disease. To save the crop, a resistant variety was discovered. Today, Panama Disease has evolved to attack the resistant variety, thus threatening to decimate banana production for a second time. This time, however, there is not a fallback option.
Note: This is an archived post. You can read the current version of this post here. Unlike most fungal rusts, Cedar-Apple Rust produces large fruiting bodies during one stage in its life cycle. These structures are probably the strangest-looking fruiting bodies found in North America.