Minnesota Fungi

Cortinarius is the largest genus of gilled mushrooms. There are estimated to be over 1,000 species worldwide. The common name “Cort” used here refers to all fungi in the genus, most of which have no individual common name, many of which remain unclassified. Corts are identified by a silky or cobwebby protective veil covering the developing gills of the young mushroom; spores that are rusty-brown or cinnamon-brown; and their occurrence on the ground in woodlands.

The species Cortinarius atkinsonianus is common and widespread in eastern North America. It is found on the ground either scattered or growing close together (gregarious) but not in clusters. It is sometimes found in rings or arcs. It appears in the fall under or near hardwoods in deciduous and mixed forests and woodlands.

The cap is 2″ to 6″ in diameter and the stalk is 1½″ to 4¾″ tall. There is often dirt and debris stuck to the cap because it was slimy or sticky when it emerged from the soil. It is olive-yellow and convex at first. As it ages it flattens out and darkens to deep reddish-brown from the center outwards, with the margin remaining olive-yellow. The flesh is whitish to pale yellow with lavender or violet areas. It stains lavender or violet when bruised. Many Cortinarius mushrooms are poisonous. The edibility of this species is unknown, but due to the difficulty of identifying these mushrooms it is recommended that they are not eaten.

Orange-gilled Waxy Cap (Humidicutis marginata) is a medium-sized, easily identified mushroom. It is widespread in North America but not common in the Midwest and northeast. It grows on the ground in humus, sometimes on very rotten wood, in coniferous, deciduous, and mixed forests. It may be found singly, scattered, or in small groups. It is edible but insubstantial and watery.

Three varieties are recognized; var. marginata, with an orange cap; var. concolor, with a yellow cap, more common in the northeast; and var. olivacea, with a olive-colored cap, more common in the west. The variety in most common in Minnesota is identified by the bright orange color; the cap that appears watery when wet but is never slimy; and the orange gills that retain their orange color even long after the cap has faded to yellow.

There are sixteen species of Hericium fungus, four of which occur in North America, three in Minnesota. Comb Tooth (Hericium coralloides) is by far the most common of the three. It is fairly common in northeastern United States and in Minnesota. It is found in late summer and fall in deciduous woodlands and forests, on fallen logs, branches, and dead stumps of hardwoods.

The fruiting body is a loose, open cluster of delicate branches. It is white when fresh, becoming creamy-white to buff or yellowish-tan with age. The branches are themselves again intricately branched and have rows of evenly-spaced spines, like the teeth of a comb, that hang downward. The spines are the spore-producing structures of this fungus, corresponding to the gills on many mushrooms (Agaricales). The flesh is white and edible when young and soft, but the spines become brittle with age.

Comb Tooth is similar in appearance to the other two Hericium species in Minnesota. It is the only Hericium that is intricately branched and has teeth no more than ⅜″ long.

Crown-tipped Coral (Artomyces pyxidatus) is very common and widespread eastern North America. It grows alone or in groups on dead, well rotted wood of hardwoods, especially aspen, willow, maple, and cottonwood. It can be found throughout Minnesota from spring through fall. It is edible but tough and stringy. It has a peppery taste when raw that goes away when cooked.

The fruiting body is a candelabra-like profusion of whitish, upright branches with a tiny, crown-like tip. The branches turn brownish as they age. Occasionally, the tips of the branches are brown.

Crown-tipped Coral looks superficially similar to many club and coral fungi. It is identified by its growing on wood; the whitish or yellowish color when young; and the crown-like depression at the branch tips with 3 to 6 points.

Morel mushrooms (Morchella spp.) are some of the best known and most sought after wild mushrooms in North America. They are particularly abundant in the upper Midwest. They are edible, considered delicious, and are hunted for in deciduous woodlands every spring. False morels (Gyromitra spp.) look superficially similar and appear at the same time of year in roughly the same areas. However, false morels are poisonous. They contain the chemical gyromitrin, which is metabolized in the body into a volatile chemical used as a rocket propellant.

Gabled False Morel (Gyromitra brunnea) is the most common false morel in Minnesota and Wisconsin. It is found in the spring, alone or in groups, on the ground under hardwood trees. The cap is tan to reddish-brown, 2″ to 4″ wide, and loosely wrinkled. It is usually saddle-shaped or winged, divided into 2 or 3 strongly projecting lobes that are fused to each other.

Cinnabar Polypore (Pycnoporus cinnabarinus)

Snow Morel (Gyromitra gigas)

American Eastern Yellow Fly Agaric (Amanita muscaria var. guessowii)

False Morel (Gyromitra esculenta)

Cedar-apple Rust (Gymnosporangium juniperi-virginianae)

Elm Oyster (Hypsizygus ulmarius)

Sharp-scaly Pholiota (Pholiota squarrosoides)