Härkönen's amanita

A whitish-to-pale Amanita of section Phalloideae bearing the group's lethal signature - white free gills, a ring on the stem and a sac-like basal volva.

Its detailed appearance is still poorly documented, which is itself a reason for caution.

Placed in the deadly Phalloideae section and suspected to carry amatoxins, it grows in the miombo woodlands where edible wild Amanitas are a staple - exactly the setting where a deadly look-alike is most dangerous.

Because it is so little studied, treat any unidentified white or pale Amanita here as potentially lethal.

Amatoxins - cyclic octapeptides, chiefly α-amanitin - shut down RNA polymerase II, so cells stop making protein and the liver and kidneys fail.

They are not destroyed by cooking, drying, freezing or soaking.

Poisoning runs in four phases:

1. 1A symptom-free latency of 6-24 hours.
2. 2Then violent vomiting and watery diarrhoea.
3. 3Then a deceptive false recovery of one to three days while liver enzymes quietly climb.
4. 4Then liver and kidney failure on days 3-5, often fatal without intensive care or a liver transplant.

The long silent start is what makes it so deadly - victims rarely connect their illness to the meal.

Never eat it. Amatoxins survive all cooking and preservation, and the delayed onset hides the danger until organ damage is underway.

Always uproot the whole stem to check for a volva, and treat every white-gilled, white-spored mushroom with a ring and a sac-like base as lethal.

Ectomycorrhizal with miombo woodland trees (Brachystegia, Uapaca) in Tanzania and Madagascar, fruiting with the rains.

Appears in the miombo rains of the southern tropics, its timing set by the local wet season.

An ectomycorrhizal Amanita: the mycelium lives for years threaded through tree roots.

A fruitbody is only the brief above-ground tip of that partnership, pushed up within a few days of warm rain.

• The edible miombo Amanitas eaten across the region
• Other pale Phalloideae species
• The introduced death cap in planted forest