Rhodotus palmatus commonly known as the wrinkled peach nearly hypnotized me when I first came across it. The wrinkles on its cap, vibrant shade of orange-pink and varying gill lengths beneath its cap make this species a stunner to look at. I knew that eventually I would have to dedicate a Fungi Friday to it, and today, we finally come face to face with this charismatic species! One can find this fungus growing from felled hardwoods in the Eastern half of North America, Europe and throughout most of Asia.
In Europe, this mushroom is exceedingly difficult to find which has led to its placement on the endangered Red List in more than half of all European countries. In 12 countries, R. palmatus is considered as near threatened, endangered, or critically endangered. Alarmingly, in the Baltic the species is considered regionally extinct. If you type the name of this fungus into the mycological cataloging website- http://mushroomobserver.org , nearly all of the specimens found are from Eastern United States, showing its higher prevalence in North America.
R. palmatus is a pioneer species when it comes to decomposition. Unlike many Galerina species that prefer latter succession woody substrates largely broken down by subsequent fungi, R. palmatus has an affinity for freshly felled hardwoods. Many specimens are found fruiting from elm trees, with a lesser occurrence found on horse chestnut, basswood and maple. Many species that specialize on freshly fallen trees tend to be latently present within the wood. Spores of latently present saprotrophs that land on a living suitable host tree can live in a dormant state within the tree for several years until the plant finally dies. It is only then when the decomposer goes to town on the carbon rich organic material within.
If you look up this fungus yourself, you will notice that it varies in its appearance quite a bit. Some have extremely defined cap wrinkles, while others are smoother. Their colors too vary, from electric pink, to pale peach, to more dominating yellow hues. Back in 1980, researchers Orson Miller, John Palmer and Linnea Gillman wanted to better understand what drove this variance in the species appearance. With their work, we now know that the spectrum of available light that penetrates to the forest floor drives the species variability.
Most other species of fungi utilize light from the shorter blue wavelength to time the different phases of its development. These aforementioned researchers discovered that the fruiting of R. palmatus occurs with the longer red, yellow and green wavelengths of the visible spectrum. In their laboratory study, they found out that under more green light, fruiting bodies produce deep wrinkles and appeared more pale peach. In the field, this phenotype would be found growing beneath a dense green canopy, as broadleaf trees throughout the growing season filter the blue and red spectrum, only allowing more of the green light to penetrate to the forest floor. When grown with red and yellow spectrum light, fruiting bodies produce less wrinkles and appeared pale or more bright orange. This phenotype would occur in broadleaf forests in the midst of fall while yellow and red leaves still remained attached.
This is without a doubt a bucket list species for me! I learned today that I have a better chance of finding it in my own neck of the woods, but finding it in Europe would really be a treat. This fungus is a special species that really just motivates me to keep learning about the natural world through a mycological lens. This planet is fascinatingly diverse, and I just really hope that future generations get see and learn about extant species rather than extinct ones. The forest floor is a gold mine of biological activity, and I think that the more we understand it, the more we will appreciate it. Our appreciation will radiate directly to conservation effort to preserve these natural communities that have been living far longer than we have.
If you have read this far, I’d just like to apologize for the lack of blog entries this past week. I started a new job teaching environmental biology at Buffalo State, so I have been allocating most of my time and energy to generating material for class lectures. I can ensure you that I haven’t run out of material for FFN, just experiencing a transitional period that I will, without question adjust to. Again, thanks for your ongoing support! Happy Fungi Friday!