The featured mushroom for January 2012 was: Chlorophyllum molybdites: the green-spored Lepiota
The Chlorophyllum molybdites is the species that almost always leads the annual list that the North American Mycological Association compiles of reported mushroom poisonings. It can be a cause of severe gastro-intestinal upsets (vomiting, diarrhea), sufficiently severe to require hospitalization to rehydrate. The green-spored Lepiota is a large, beautiful mushroom that closely resembles some edible mushrooms. In the button stage it can be confused with shaggy manes, Coprinus comatus. In the mature stage it can be confused with two excellent edibles: shaggy parasols, Lepiota rachodes (aka Macrolepiota rachodes) and parasols, Lepiota procera (aka Macrolepiota procera). C. molybdites can also resemble edible species of the genus Agaricus.
C. molybdites is a large stately mushroom with a convex to flat cap from 2 to 12 inches wide and a stem from 2 to 10 inches tall and 3/8 to 1 inch wide. The cap is whitish with brown or pinkish-brown tissue that very soon breaks up into small scales and patches on the cap. The scales tend to curl upward with age and tend to be concentrated near the center of the cap. The flesh is white sometimes bruising orange. The veil is membranous forming a double-edged persistent ring on the stem that can be movable in age like the ring of the very similar shaggy parasol. The gills are free, close and broad, white at first becoming dirty gray-green or darker as the spores mature. The spore print is grayish-green to green. The habitat is grassy areas like lawns and meadows. The mushroom frequently grows in fairy rings.
The button stage (the stage with an intact partial veil enclosing the gills) of the green-spored Lepiota tends to be more globe-shaped when compared to the more conical buttons of the shaggy manes. The mature stage tends to have scales more concentrated at the center of the cap then the shaggy parasol whose scales are all over the cap. The habitat of the green-spored Lepiota is grasslands whereas the shaggy parasol occurs in rings on the ground under trees (especially conifers). The habitats can overlap though. The only completely reliable difference between the green-spored Lepiota and the shaggy parasol is the spore print. The spore print of the true parasols (L. rachodes and L. procera) is white, the spore print of Agaricus species is chocolate brown and the spore print of the shaggy mane is black.