The field mushroom (Agaricus campestris) is easy to get right: when genuinely pre-armed with the right knowledge (see list below), identification can be easy; when taken home it is so similar to its domestic cousin (the ‘common’ mushroom, Agaricus bisporus) that it is easy to cook (if a bit moister); and this then makes it easy to serve even to people who would otherwise abstain from a wild fungus. That said, it can also be relatively easy to get wrong.
The death cap mushroom (Amanita phalloides), which kills more people worldwide than any other, looks a bit like a field mushroom. Recent deaths in Canberra, and in other documented cases with Asian foragers, can be attributed to the similarity of the death cap to the Asian paddy straw mushroom (Volvariella volvacea) more than to field mushrooms, but confusion with field mushrooms has also occurred. The yellow staining mushroom (Agaricus xanthodermus) might also catch you out and make you sick although at least not dead. The literature suggests that there are a few more similar types that occur in Australia like the European blusher (Amanita rubescens), but it remains that with the right precautions, it is certainly possible to distinguish these from field mushrooms. With the overriding maxim ‘if in doubt, go without’ I am now confident in a field mushroom using the following checklist (this is NOT all you need to know, but should hopefully help):
- It looks like a common mushroom, albeit maybe larger, with an essentially white top that may get grey-brownish with age but not any type of yellowish and certainly not at all greenish. Richard Mabey, in the foraging bible Food for Free, suggests that the best place to study for identifying field mushrooms (presumably excluding being alongside an experienced gatherer) is at the mushroom shelf in the grocers.
- It is growing in a paddock where herbivores crop the grass and enrich it with manure (most commonly cows, but also horses, sheep and I’ve even done well where kangaroos do the job) – not always the case (lawns can also have them), but a safe precaution.
- There are a few of them in the same area and which can be seen to show that the mycelium (the underground fungal network from which the mushrooms are just fruiting bodies) is in the dirt under grass and not associated with tree roots. It is probably easiest to just have no trees nearby, particularly introduced ones, and especially but not exclusively oak;
- The gills are at the very lightest a pinkish brown in the youngest ones and definitely a dark brown in older specimens, and when pressed on paper, the ‘spore print’ is also dark (white gills and spore print are a characteristic of death caps as well the ‘destroying angel’ (various other Amanita spp.) that occurs in other parts of the world).
- The stipe (or stem) is white with a single thin ring of skin where the cap once attached. It definitely does not have a sheath at the base;
- When the stem is cut it stains at most faintly red-brownish and definitely not yellow (as in the yellow staining mushroom), nor pink and not at all blueish (like the powerfully hallucinogenic ‘gold top’ magic mushroom of warm humid cow fields, Psilocybe cubensis);
- When cut, and also importantly after some time stored, it does not have a notable smell (death caps are described as smelling from ‘honey sweet’ to ‘objectionably sweet’ and yellow staining mushrooms as ‘phenolic or soapy’ especially at the base and noticeably with cooking).
Driving in to the cabin last weekend, a few white buttons were showing in a neighbour’s paddock – in a corner where cows often congregate and therefore manure. Speaking to another neighbour I suggested they would likely reveal themselves to be field mushrooms and that I would get them on the way out; he added that he was entirely certain they were field mushrooms and that he’s been eating them from there for years. On the way out they had opened up ready for harvest. I cut them, check for a ring but no sheath, dark brown gills, dark spore print, no odour, no staining and general similarity to button mushrooms.
In the past, before I had gotten the mushrooming bug, I have gone past many mushrooms I thought were probably field mushrooms but left them appropriately untouched because probably was as close my knowledge could get me. I have since armed myself with enough knowledge to confidently take at least the most obvious. My first field mushrooms were on the farm where my father grew up. The most recent before these were at the farm my mother grew up on. I grew up in the city, but for my son at least, his first field mushrooms were from the land he will hopefully grow up with. Last Monday, in a vegie bolognaise with noodles.