Similarity to edible species
Recent cases highlight the issue of the similarity of A. phalloides to the edible paddy straw mushroom, Volvariella volvacea, with east- and southeast-Asian immigrants in Australia and the west coast of the United States falling victim. In an episode in Oregon, four members of a Korean family required liver transplants (Benjamin 1995). Of the seven people poisoned in the Canberra region between 1988 and 1998, three were from Laos (Trimm et al. 1999). This misidentification is a leading cause of mushroom poisoning in the United States.
Novices may mistake juvenile death caps for edible puffballs (Hall et al. 2003) or mature specimens for other edible Amanita species such as Amanita lanei, and for this reason some authorities recommend avoiding the collecting of Amanita species for the table altogether (Phillips 2005). The white form of A. phalloides may be mistaken for edible species of Agaricus, especially the young fruitbodies whose unexpanded caps conceal the telltale white gills; all mature species of Agaricus have dark-coloured gills (Heino 2006).
In Europe, other similarly green-capped species collected by mushroom hunters include various green-hued brittlegills of the genus Russula and the formerly popular Tricholoma flavovirens, now regarded as hazardous owing to a series of restaurant poisonings in France. Brittlegills, such as Russula heterophylla, R. aeruginea, and R. virescens, can be distinguished by their brittle flesh and the lack of both volva and ring. Other similar species include A. subjunquillea in eastern Asia and A. arocheae, which ranges from Andean Colombia north at least as far as central Mexico, both of which are also poisonous.References
- Benjamin, Denis R. (1995). Mushrooms: poisons and panaceas — a handbook for naturalists, mycologists and physicians. New York: WH Freeman and Company.
- Hall IR, Stephenson SE, Buchanan PK, Yn W, Cole AL. (2003). Edible and poisonous mushrooms of the world. New Zealand Institute for Crop & Food Research Limited, 131-3.
- Heino, Lepp (9 October 2006). Deathcap Mushroom: Amanita phalloides. Australian National Botanic Gardens.
- Phillips, Roger (2005). Mushrooms and Other Fungi of North America. Buffalo: Firefly books, p.14
- Trim Geoffrey M. et al. (September 1999). Poisoning by Amanita phalloides ("deathcap") mushrooms in the Australian Capital Territory. Medical Journal of Australia 171 (5): 247–249.
- Zeitlmayr, Linus (1976). Wild Mushrooms:An Illustrated Handbook. Hertfordshire: Garden City Press.
Don't confuse the Deathcap with the Straw Mushroom
The Straw Mushroom (Volvariella volvacea) is grown and eaten through a large part of Asia but it does not grow naturally in Australia. However the species Volvariella speciosa is found naturally in many parts of Australia and looks very similar to the Straw Mushroom. Each species in Volvariella has a volva at the base of the stem and the gills don’t reach the stem - just like the Deathcap. However, in Volvariella there is no ring on the stem and the gills are pale pinkish-brown, rather than white. Moreover, the cap is more brown to greyish and more-or-less conical. However, you could easily overlook some of these differences in a hasty examination and much depends on the weather. Just to prove that point, here is another photo, taken in Canberra, showing a Volvariella speciosa and a half-open Deathcap. There were several specimens of each species growing together, in a small parkland area. The photo was taken a day after heavy rain, so both mushrooms have been battered by the weather. Can you pick the Deathcap?
If you have migrated from Asia, or are otherwise familiar with the Straw Mushroom, you could accidentally pick a Deathcap, thinking it is the harmless Straw Mushroom. In one Canberra case, three Laotians made this mistake and the same mistake has also been made in New Zealand and the USA.
Could I confuse the Deathcap with anything else?
You shouldn’t confuse it with any of the ordinary field mushrooms (in the genus Agaricus), where the gills are pink at first but eventually turn brown. Mushrooms in the genus Agaricus also have a ring on the stem, but no volva at the base of the stem. Here are the undersides of a couple of Agaricus species, showing pink and brown gills.
When the Deathcap is still very young, it is enclosed in a smooth, white skin. You could initially mistake this stage for an immature puffball, since many puffballs are white when young. However, while an immature puffball has solid white flesh inside, a young Deathcap will show the stem and gills. This photo, of a young Deathcap cut in half, shows this. On the right is the outside appearance and on the left is the inside - showing the young stem and gills.