Toadstool Tuesday
Fragile Dapperling (Leucocoprinus fragilissimus)
Good evening, friends,
The past week of rain has led to plenty of fungal finds. The NYMS walk in Harriman State Park on Saturday produced the greatest fungal diversity I’ve seen this year despite the feeling that many mycorrhizals still seem to be dormant. This week’s mushroom comes from the preserve, however. The Fragile Dapperling (Leucocoprinus fragilissimus) popped up for a short time, but a good time, on Wednesday. I saw these ephemeral little umbrellas once earlier in July, but this is the first summer I’ve seen them on the preserve. A new species to me, let’s take a closer look.
Fun Facts
This mushroom may look familiar because a similar species can grow right in your living room. The Flowerpot Parasol (Leucocoprinus birnbaumii) is a tropical mushroom that is frequently found growing from the soil of house plants. Still waiting on them to pop up in my living room though :/
Far from the living room (hopefully), leaf cutter ants (Attini) will cultivate a species of Leucocoprinus in their nests. Found in tropical regions across the globe, a mature leaf cutter colony can harvest up to 75 lbs of leaves a day which they feed to the fungus (often but not always Leucocoprinus). I consider myself a big eater, but even I have to tip my cap to 75 lbs a day. All this so that the ant larvae can use the fungal mycelium as food. There are a lot of intricate nuances in the relationship that includes the ants using a bacteria that grows on their body as an antimicrobial to keep the fungus healthy.
The etymology of Leucocoprinus is derived from the Greek Leuco- which means white and -coprinus which means dung (but also relates to the physically similar fungal genus Coprinus). The species epithet fragilissimus does, indeed, mean fragile but the suffix -issimus emphasizes it to the highest degree (fortis = strong → fortissimus = strongest).
Ecology
The fungus is saprobic and digests organic matter on the forest floor. The mushrooms are very dependent on available moisture and humidity, and their fragility gives them less than twenty-four hours in the woods. Though they’re short-lived, I saw several of them growing over at least a twenty foot swath of forest which makes me think the mycelium is robust. The caps are deeply grooved and feature a dark point in the center where the stipe attaches.
The mushrooms can be found on the six inhabitable continents; the majority of iNaturalist observations are from eastern North America, South America, and eastern Asia. I imagine there are several genetically unique, but physicically similar, species that masquerade under the one species L. fragilissimus. The mushrooms grow in the summer months when those hot and humid environmental conditions are just right.
This weekend
8/17: A walk with the Stamford Land Conservation Trust at the end of Mill Stream Road at 10AM.
8/18: A walk with the Mid-Hudson Mycological Association at Fahnestock State Park at 11AM. Meet in the lot at the intersection of Dennytown and Sunken Mine Road.
An MM reader from the Central Park days, Diane informed me that the annual Perseid meteor shower is happening right now. The shower peaked in intensity on Monday morning, but you can look up and see these meteors race across the night sky all the way into early September.
Look up,
Aubrey
References
Kuo, M. (2015, May). Leucocoprinus fragilissimus. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/leucocoprinus_fragilissimus.html
Weber NA. Fungus-growing ants. Science. 1966 Aug 5;153(3736):587-604. doi: 10.1126/science.153.3736.587. PMID: 17757227.
https://www.inaturalist.org/taxa/202380-Leucocoprinus-fragilissimus