Mushroom of the Month for October 2013 was the
Lepiota rachodes, aka Macrolepiota rachodes: the Shaggy Parasol
The shaggy parasol is a large, fleshy mushroom that is excellent eating. Some people have had severe reactions to the shaggy parasol especially on the West Coast. On the West Coast there is a close look-alike, Lepiota brunnea which is poisonous; possibly the poisonings reported are from misidentification. Shaggy parasols caps at maturity can be eight inches across and can stand seven inches high.
Shaggy parasols start as a button with a smooth, tan or light brown cap two to three inches wide. As the mushroom matures like many Lepiotas, the skin of the cap breaks up leaving a beige central patch surrounded by concentric circles of reddish brown scales with the white flesh appearing between scales. The scales of the shaggy parasol are coarse but smooth with a slight downcurl. The cap of the shaggy parasol is 2-8 inches wide. The gills are free, close broad and white to cream darkening with age to a dirty buff. The smooth, white stem is 2-7 inches tall and 3/8 to 1 inch thick with a persistent, double edged, moveable ring on the upper stem after the membranous partial veil ruptures. The thick, firm flesh is white sometimes discoloring to orange or reddish when cut or bruised. The staining is most prominent at the base of the stalk where the white bulb discolors reddish to orange. The spore print is white. The shaggy parasol grows in small groups or fairy rings on ground under trees (especially conifers), in gardens, compost piles, near stables, along roads and other disturbed places.
Chlorophyllum molybdites, the green-spored Lepiota, is a fairly dangerous look-alike for the shaggy parasol. Chlorophylloum molybdites is a bad sickener with symptoms that usually begin within two hours of consumption including thirst, nausea, confusion, chills, sweating, abdominal pain, vomiting (often violent) and diarrhea (sometimes bloody). Hospitalization is sometimes required to alleviate the symptoms and to rehydrate the patient. The primary difference between the shaggy parasol and green-spored Lepiota is the green spore print. Young specimens whose gills have not begun to turn green are a dead ringer for young shaggy parasols. Though shaggy parasols are more often associated with trees and green-spored Lepiotas are most often grass mushrooms, the habitats can overlap. Other Lepiotas can be mistaken for the Shaggy Parasol also. The parasol, Lepiota procera, is a taller, less fleshy species with a scaly stalk. Lepiota americana grows in clusters and has a spindle shaped stalk. Many small Lepiotas are poisonous but their diminutive size makes it unlikely that a collector would confuse them with any of the large Lepiotas: L. procera, L. rachodes, or L. Americana.