Entoloma sinuatum
Description
Entoloma sinuatum is a poisonous mushroom found across Europe and North America. Some guidebooks refer to it by its older scientific names of Entoloma lividum or Rhodophyllus sinuatus. The largest mushroom of the genus of pink-spored fungi known as Entoloma is also the type species.
Appearing in late summer and autumn, fruit bodies are found in deciduous woodlands on clay or chalky soils, or nearby parklands, sometimes in the form of fairy rings. Solid in shape, they resemble members of the genus Tricholoma. The ivory to light gray-brown cap is up to 20 cm (8 in) across with a margin that is rolled inward. The sinuate gills are pale and often yellowish, becoming pink as the spores develop. The thick whitish stem has no ring.
When young, it may be mistaken for the edible St George's mushroom (Calocybe gambosa) or the miller (Clitopilus prunulus). It has been responsible for many cases of mushroom poisoning in Europe.
Entoloma sinuatum causes primarily gastrointestinal problems that, though not generally life-threatening, have been described as highly unpleasant. Delirium and depression are uncommon sequelae. It is generally not considered to be lethal, although one source has reported deaths from the consumption of this mushroom.
Common names: Livid Pinkgill, Lead Poisoner.
Mushroom Identification
Cap
Ivory white, darkening with age; conical then convex to plane with a blunt umbo; slightly sticky when young; margin sometimes lobed. Entoloma sinuatum is the largest of the Entoloma species, with caps ranging from 6 to 20 cm across when fully expanded.
In very hot weather the cap edge tends to split as the down-turned margin flattens.
Gills
Yellowish white initially, the sinuate, crowded gills of Entoloma sinuatum turn more pinkish as the spores mature.
Stem
Ivory white; smooth; cylindrical but sometimes bulbous at the base; 3 to 10cm long, 0.6 to 1.5cm diameter; no stem ring.
Spores
Subglobose, angular, 7-10 x 7-9µm, with an extremely prominent germ pore.
Spore print
Pink.
Odor and Taste
Odor vague but rather unpleasant; taste not distinctive.
Season
Fruiting from early summer to late autumn in Britain and Ireland but continuing into the New Year in Mediterranean countries.
Similar Species
This pale-capped mushroom could be confused with St George's Mushroom, Calocybe gambosa, which usually fruits from Springtime until early summer, has white gills and a distinctly mealy odor.
Many other white or pale-capped fungi occur in similar habitats - Clitocybe nebularis, is one such example - but gill color and odor help differentiate them from pale Entoloma species.
History
This species was described scientifically by Jean Baptiste Francois (Pierre) Bulliard in 1788 when he named it Agaricus lividus. However, the first valid name (under the current ICBN rules) is now Agaricus sinuatus, given to it when Christiaan Hendrik Persoon described this species in 1801. In 1871 the famous German mycologist Paul Kummer transferred this species to its present genus, renaming it Entoloma sinuatum.
Synonyms of Entoloma sinuatum include Agaricus sinuatus Pers., Entoloma lividum (Bull.) Quel., Rhodophyllus lividus (Bull.) Quel., and Rhodophyllus sinuatus (Bull.) Quel.
Entoloma sinuatum is the type species of the Entoloma genus.
The generic name Entoloma comes from ancient Greek words entos, meaning inner, and lóma, meaning a fringe or a hem. It is a reference to the inrolled margins of many of the mushrooms in this genus.
More obviously, the specific epithet sinuatum is a reference to the sinuous or wavy nature of mature caps (and the gills are sinuate too!), while the former specific name lividum means leaden (lead-colored) - not inappropriate for a toxic toadstool that was once most commonly referred to in Britain as the Lead Poisoner.
Toxicity
This fungus has been cited as being responsible for 10% of all mushroom poisonings in Europe. For example, 70 people required hospital treatment in Geneva alone in 1983, and the fungus accounted for 33 of 145 cases of mushroom poisoning in a five-year period at a single hospital in Parma.
Poisoning is said to be mainly gastrointestinal; symptoms of diarrhea, vomiting and headache occur 30 minutes to 2 hours after consumption and last for up to 48 hours. Acute liver toxicity and psychiatric symptoms like mood disturbance or delirium may occur.
Rarely, symptoms of depression may last for months. At least one source reports there have been fatalities in adults and children. Hospital treatment of poisoning by this mushroom is usually supportive; antispasmodic medicines may lessen colicky abdominal cramps and activated charcoal may be administered early on to bind residual toxin.
Intravenous fluids may be required if dehydration has been extensive, especially with children and the elderly. Metoclopramide may be used in cases of recurrent vomiting once gastric contents are emptied.
The identity of the toxin(s) is unknown, but chemical analysis has established that there are alkaloids present in the mushroom.
A study of trace elements in mushrooms in the eastern Black Sea Region of Turkey found E. sinuatum to have the highest levels of copper (64.8 ± 5.9 μg/g dried material—insufficient to be toxic) and zinc (198 μg/g) recorded. Caps and stalks tested in an area with high levels of mercury in southeastern Poland showed it to bioaccumulate much higher levels of mercury than other fungi.
The element was also found in high levels in the humus-rich substrate. Entoloma sinuatum also accumulates arsenic-containing compounds. Of the roughly 40 μg of arsenic present per gram of fresh mushroom tissue, about 8% was arsenite and the other 92% was arsenate.
Photo sources:
Photo 1 - Author: Holger Krisp (CC BY 3.0)
Photo 2 - Author: Gerhard Koller (CC BY-SA 3.0)
Photo 3 - Author: Entoloma_Sinuatum_1.JPG: Archenzoderivative work: Ak ccm (talk) (CC BY-SA 3.0)
Photo 4 - Author: zaca (CC BY-SA 3.0)
Photo 5 - Author: zaca (CC BY-SA 3.0)
