Chlorophyllum molybdites: The Ultimate Mushroom Guide

About The Chlorophyllum molybdites Mushroom

Chlorophyllum molybdites also know as a false parasol, green-spored Lepiota, and vomiter is a widespread mushroom. Highly poisonous and producing severe gastrointestinal symptoms of vomiting and diarrhea, it is commonly confused with the shaggy parasol or shaggy mane, and is the most commonly consumed poisonous mushroom in North America.

This large poisonous mushroom appears in summer and fall, most often in urban areas like schoolyards, neighborhood lawns, and parks.

Its large size and similarity to the edible parasol mushroom, as well as its habit of growing in areas near human habitation, are reasons cited for this. The nature of the poisoning is predominantly gastrointestinal.

Chlorophyllum molybdites Identification

1. Cap

   Cap is 5-30 cm wide; oval, then broadly convex to flat; dry; white with buff patches on center when young, then white with light brown scales; flesh white, not staining when bruised or bruising dingy reddish-brown; in button stage often bruises reddish-brown within 60 seconds.

   Sometimes the young mushrooms grow elongated. When they look like this, they can be confused with edible shaggy mane mushrooms. Learn more below in the "confusion with other species" section.

2. Gills

   The gills are white at first, becoming greenish-gray and not attached to the stalk but close.

3. Stalk

   The stalk is smooth, white or a whitish-brown, 5-25 cm long, 1-2.5 cm thick at apex, enlarging at base; smooth; white, discoloring brownish. Ring: double-edged, often movable.

4. Annulus

   The annulus is large, persistent, becoming double-edged, white on the top and brown beneath, moveable, but located near the top of the stalk.

5. Spores

   Spores print green, 9.5-12 x 6.5-9, elliptical, thick-walled with apical pore, smooth, dextrinoid.

Chlorophyllum molybdites Habitat

Chlorophyllum molybdites can appear from spring to fall but is most often seen in when the spring gets warm, (May in most parts of the US, and April in the South) through the warmer months of fall (September in much of the country, October and into November in the South and Southwest).

Of course, these are rough estimates. The mushroom can grow whenever it's warm enough for it, and that can vary from year to year. It is not a mushroom you will see while there are frosts, however.

Most frequently you can encounter Chlorophyllum molybdites in the grass, especially lawns and parks after watering. Despite this, you can also found them along pathways and frequently in wood chips.

In New Jersey, this mushroom was more likely to grow alone, or in small, scattered groups, and to grow very large (8" or more across).

In Texas, the mushrooms are generally smaller (4"-6" at full size), but to grow in larger clusters, arcs, fairy rings, or groups.

What's the difference between Chlorophyllum rhacodes and Chlorophyllum molybdites?

The most distinct characteristic is size, these mushrooms can be up to a foot tall, and their parasol top is huge.

Secondly, the distinctive cap. Its "shaggy" appearance comes from flaked dark skin on the top of the mushroom exposing a lighter color underneath.

Thirdly, they have brown spores, NOT green which will become important later on in this article.

Chlorophyllum molybdites Toxicity

The Green Spored Lepiota is the worst GI irritant mushroom. In fact, the symptoms are different enough from those produced by other GI irritant mushrooms that the North American Mycological Association’s webpage on mushroom toxins lists Chlorophyllum molybdites separately.

Symptoms appear between one and two hours after eating the mushroom and can include: nausea, dizziness, vomiting, abdominal pain, and diarrhea. These symptoms can vary in severity due to differences in weather, individual mushrooms, and each person’s age and sensitivity.

In the worst cases, sufferers can have bloody, explosive diarrhea and may need hospital treatment. The toxin(s) involved are not yet known, so treatment of Chlorophyllum molybdites poisoning focuses on alleviating symptoms: doctors administer drugs to counteract the vomiting and diarrhea and administer fluids and electrolytes when necessary.

Chlorophyllum molybdites Taxonomy

You may have noticed the word “chlorophyll” in the name Chlorophyllum molybdites. There is a good reason for this: chlorophyll is derived from the words ‘chloro’ meaning ‘green’ and ‘phyllum’ meaning leaf. Chlorophyll is so named because it is the substance that turns plant leaves green. Similarly, the name Chlorophyllum denotes the green gills of C. molybdites (taxonomists don’t have a separate word for ‘mushroom gills’, so they just use the word for ‘leaves’).

The classification of C. molybdites, like that of many agarics, has changed a lot over the years. Most significantly, it once belonged to the genus Lepiota. Its common name – the “Green Spored Lepiota” – was established at that time. The name used publicly for this mushroom has not changed since, even after mycologists reassigned it to Chlorophyllum. C. molybdites is now just one of a multitude of mushrooms whose common names reflect outdated taxonomy.