Chlorophyllum molybdites is a highly poisonous species of fungus, despite its common names like Green-spored Lepiota or False Parasol. Consuming it leads to severe gastrointestinal distress. This mushroom is the most frequent cause of mushroom poisoning cases reported across North America. Its large, inviting appearance and tendency to grow in lawns and grassy areas are the main reasons for accidental ingestion. Anyone finding this species should treat it with caution and ensure neither people nor pets consume it.
Key Characteristics for Identification
The cap of Chlorophyllum molybdites is typically large, ranging from four to twelve inches in diameter, and is whitish to tan with coarse brownish scales concentrated toward the center. When young, the cap is rounded, expanding to become broadly convex or flat at maturity. A prominent, movable ring is present around the stem, a feature shared with its edible relatives.
The gills are initially white but transition to a greenish-gray color as the specimen matures. This change in gill color is an important visual cue for identification. The single most reliable feature is the spore print, which is a light sage or olive-green color. This green spore color is virtually unique among the large, white-gilled mushrooms it is commonly mistaken for.
The Gastrointestinal Toxicity Status
The illness caused by ingesting this species is classified as severe gastroenteritis, triggered by potent gastrointestinal irritants. The primary toxin is a high-molecular-weight protein named molybdophyllysin, a type of zinc protease. This compound acts directly on the lining of the digestive tract, causing irritation and inflammation.
The toxins are present throughout the entire mushroom, with the highest concentration typically found in the cap. Although the poisoning is rarely fatal, it is a severely sickening event due to the intensity of the symptoms. Unlike deadly fungi such as those in the Amanita genus, Chlorophyllum molybdites does not contain toxins that primarily target the liver or kidneys.
Symptoms Following Ingestion and Necessary Action
Symptoms of poisoning usually begin rapidly, often within one to three hours after consumption. The onset is marked by violent vomiting, severe abdominal pain, and profuse diarrhea. In severe cases, the diarrhea may become bloody, indicating significant irritation of the intestinal lining.
The rapid fluid loss from vomiting and diarrhea can quickly lead to dehydration and electrolyte imbalance. Children and the elderly are particularly susceptible to complications like hypovolemic shock due to their limited capacity to handle fluid loss. Most patients recover fully within 24 hours with supportive care, but symptoms can persist for up to a week.
Necessary Action
If ingestion is suspected, immediately contact a local Poison Control Center. Seek medical attention promptly to manage dehydration and stabilize electrolyte levels through intravenous fluid therapy. If possible, save a sample of the mushroom or any vomit for professional identification, as this information guides treatment decisions.
Common Edible Mushrooms Mistaken for Chlorophyllum Molybdites
The frequent misidentification of Chlorophyllum molybdites is the main reason for its high poisoning rate. It is commonly confused with edible species like the true Parasol mushroom (Macrolepiota procera) and the Shaggy Parasol (Chlorophyllum rhacodes). These desirable look-alikes share the general shape, size, and presence of scales on a large cap.
The distinguishing difference between the toxic and edible species lies in the color of the spores. Edible members of the family, such as Macrolepiota procera, produce a white or cream-colored spore print. This contrasts sharply with the unique sage-green spore print of C. molybdites. Foragers should never consume a wild mushroom unless they have confirmed the spore color.