Another rainy week in the woods of northern Minnesota but I have no choice and must work in it if I am to finish this project on time. My goals were to survey one upland forest and four conifer swamps. The first day was in an old growth sugar maple forest. It was easy walking once I got up the boulder strewn slope and onto the gently rising hill where the sugar maples grow. The weather was mild and partly sunny. A breeze coming from Lake Superior kept the black flies and mosquitoes down. I covered a good portion of the forest I had not been to on my previous visit. The principle tree is sugar maple and many of them are large with trunks 2 to 3 feet in diameter. There are smaller ones, too, growing in the under-story. If or when any of the larger and older trees fall over in a storm or die from old age these smaller trees will quickly fill in the gaps.
Late Tuesday night until Thursday morning it rained. In some places the rainfall was heavy and small streams flooded. The swamps also filled with water from the runoff. Temperatures became much cooler and this was made only worse by the fog and light wind. Everything was soaked. Water dripped from every leaf and pine needle. To grab a branch for balance when trying to climb over dead-falls meant getting rained on again. At the end of each day I was mostly dry thanks to rubber boots, rain pants, and a raincoat. I stayed warm, too, because under the rain gear I was wearing lined pants, thick socks, a heavy shirt and sweater almost like it was winter. My tent and sleeping gear were dry when I got back to camp and that was a relief. I’ve had to sleep in flooded tents and wet sleeping bags before and it is no fun at all.
In spite of the rain and cooler weather, I made good time and covered a lot of territory. I also found a few interesting plants and lichens that will need to be revisited later this summer on a dry day. Now I am home again sorting through data and photos, cleaning my gear, and preparing for next week. And there is weeding to do, grass to cut, gutters to clean, and getting another wall of my house ready for painting. Well, at least there are three or four days of warm weather ahead.
That weird fungus I found last year in June turns out to be two fungi. It, or rather they, were growing from a mossy decomposed log in my woods. The whole thing looked a bit like a chunk of old foam rubber. Not being an expert in fungi I started searching images with queries like “globular fungus” and “tuberous fungus”. This soon led me to truffles and their kin. Then, after seeing cross sections of these globular fungi with their layered interiors, I was steered towards the truffle relatives Geopora and Hydnocystis. By that time I was way off the path to the right identification especially after I saw an exterior shot and cross-section of Geopora cooperi which has a fuzzy exterior and distinctly convoluted interior. (See more photos of Geopora and Hydnocystis here on the Asociacion Vallisoletana de Micologia web site. But G. cooperi, as far as is known, does not grow in Minnesota. Some species of Hydnocystis are reported to grow here, though. I was close, in the right family (Pezizales), but was looking at the wrong genera and missing a very important microscopic feature.
One night I was browsing the internet about another fungus (Datronia scutellata) and came across a very informative site called Weird and Wonderful Wild Mushrooms. Going through the archives I happened upon a post on false morels. The picture of Gyromitra gigas in cross section reminded me of what I had found last year. After some communication with the blogger it turned out that this foam rubber fungus is neither Geopora or Hydnocystis but a Gyromitra, most likely G. esculenta, very common here, that has been infected by another fungus called Sphaeronaemella helvellae. The fuzz over the fungus surface was S. helvellae and not, as I first thought, a coating soft hairs on its surface. So, this is another infected mushroom!
Infection by S. helvellae does more than coat the Gyromitra with fuzz. It also deforms it and this globular deformity and the layered interior led me in the direction of truffle relatives. There are many parasitic fungi that infect other fungi. One genus, Hypomyces, contains some 53 different species that infect a huge range of gilled mushrooms including Russula, Lactarius, Suillus, and Amanita. The mushroom Psathyrella epimyces infects Coprinus, the inky caps, and there are several species of Cordyceps that infect truffles.
I was back in the woods last week but in another part of Minnesota. This area is along the edges of the eastern section of the BWCA. It differs geologically and topographically from the western parts of the BWCA. The rocks are mafic igneous rocks, usually gabbro and basalt, meaning they are rich in dark minerals such as iron and magnesium. Formations of gabbro and basalt, and Precambrian red sandstones (some with ripple marks from ancient seas), shale, and conglomerates, banded iron formation chert, and graywacke are common. These rocks form thick beds and rise steeply from Lake Superior with an abrupt elevation change going from 700 feet above sea level to 2,000 feet in just a few miles. This makes for some strenuous walking which is made only worse by the dense forest under-story to fight through and hoards of mosquitoes and gnats.
Ignoring the biting insects I saw some great scenery and explored very old forests and cedar swamps. I’ll be heading back next week to continue where I left off. For now I am home again washing clothes, sorting through maps and GPS files, and planting my tomatoes.