Lepiota subincarnata — Deadly parasol
Deadly parasol2, photograph by Adolf Ceska.
Deadly parasol7, photograph by Adolf Ceska.
Warning: These small to medium mushrooms contain deadly amatoxins. Do not confuse them with edible fairy ring mushrooms (Marasmius oreades). The cap surface of the fairy ring mushroom is smooth and tan while the surface of the deadly parasol breaks up into concentric rings of brownish scales on a white background. The stem of the fairy ring mushroom is smooth, and that of the deadly parasol has bands of felty material on it. Both species are common in lawns and mulch.
Odour: Indistinct to sweet and fruity.
Taste: Tasting not recommended (see 'Toxicity').
Cap: 1.5–6 cm in diameter, convex young, often with a broad low bump in the middle, flat when old. At first completely covered with a pink-brown velvety layer. This layer breaks open when the cap expands, resulting in concentric rings of pink-brown scales or warts on a white background. The centre remains covered by tufted-velvety material.
Gills: White, free, not attached to the top of the stem.
Stems: 1.5–5.5 cm long x 0.15–0.7 cm wide, pale cream to pink on top and with bands or scattered warts of material in lower 3/4 of stem. These bands have the same colour as the cap.
Ring or veil: A faint band of velvety material on the stem.
Cup: None.
Spores: 6–7.5 x 3–4 µm, smooth and ellipsoid, dextrinoid (turning reddish in Melzer's iodine solution).
Habitat: In lawns and gardens in the city, but also under various trees in forests. Saprotrophic.
Geographical range: Reported from Oregon, Washington and in BC, from the wider Vancouver area and southern parts of Vancouver Island. Widely distributed throughout temperate North America, Europe and Asia.
Any small mushroom with free, white gills and pink-brown, orange-brown or brown caps could contain amatoxins. Most smell unpleasant, but the most dangerous are among the sweet-smelling ones. None of these should be eaten. Lepiota josserandii is another name for the deadly parasol (L. subincarnata).
Toxins: Mushrooms in this group have amatoxins, cyclic peptides made up of 8 amino acids that stop protein synthesis by inhibiting an essential enzyme, RNA polymerase II5.
Symptoms: Time of onset 6–12 hours (–36 hours) after eating mushrooms. Abdominal pain, vomiting, and watery diarrhoea. Symptoms subside after about one day; then about 72 hours post-ingestion, gastrointestinal symptoms recur along with signs of impending liver failure. In fatal cases death occurs 7 to 10 days after the first symptoms.
Treatment: Immediately contact your regional Poison Control Centre if you realize you or someone you know has become ill after eating any Lepiota-like mushroom. Poison centres provide free, expert medical advice 24 hours a day, seven days a week. If possible, save the mushrooms or some of the leftover food containing the mushrooms to help confirm identification.
Lepiota subincarnata has caused a fatality in BC6:
- In October 1988 a man ate Lepiota subincarnata mushrooms picked from his lawn in the greater Vancouver area in a breakfast omelette, under the mistaken belief that they were fairy ring mushrooms (Marasmius oreades). He began to experience abdominal pain, severe vomiting and leg cramps 13 hours later. The following day he was admitted to hospital and two days after ingestion, his condition appeared to have improved though tests indicated that liver damage was occurring. The following day the patient experienced more nausea, abdominal pain, vomiting and occasional diarrhoea. His condition began to deteriorate four days post-ingestion, and he lost consciousness two days later. He was placed on life support after kidney and liver failure. He died nine days after eating the mushrooms.