"What's the difference between a mushroom and a toadstool?"  This is a question which is often asked, not surprisingly because it's not easy to decide.  In America I believe they are all called Mushrooms, but in this country we have got into the habit of calling some of the edible ones, usually with the latin name Agaricus, "mushrooms" and all the rest "toadstools".  In fact, they are all relatively large species of fungus and there are plenty which are excellent eating but are not called mushrooms in Britain.
  Unlike plants, no fungi can make their own food, so they either digest organic remains to get energy and grow, or they are parasites on other living things, or they barter for food in exchange for something else.  In the first group come the Field Mushrooms and Horse Mushrooms which most of us can recognise well enough to risk picking and eating them.  What we eat is simply the "fruiting body" whose gills on the underside produce microscopic spores, one in a million of which may grow into a new mushroom fungus.  Down below in the soil, however, is an enormous network of fine threads which grow slowly through the soil, digesting the remains of dead animal and plant material to get their energy, and releasing unwanted minerals into the soil.  Unless the grass has been extremely well fertilised, this gives a spurt to its growth and it looks dark green against the yellow-green grass around.  Mushrooms can live for many years, so they gradually spread outwards through the soil from their starting point, making a ring of this dark green grass.  In older specimens portions of the rings may die off, so making them difficult to see from ground level, but aerial photographs show them up well.  Indeed archaeologists were very excited when they observed many rings in the grass around Stonehenge as seen from the air and they presumed that they
represented other henge constructions, but in the end it was discovered that they were fungi, a number of which, from their diameters, must have been hundreds of years old.
  These rings have, of course, been noticed from time immemorial and the most favoured theory to account for them was that they were caused by fairies dancing in rings (which of course they do).  In fact a Wiltshire curate, a Mr Hart, saw them coming over the downs late one evening and dancing round the grass circles. He said that they enchanted him so that he couldn't run away and then they pinched him all over ……. and who are we to doubt the word of a curate?  One of these ring-causing toadstools has become known as the "magic mushroom" because of its hallucinogenic properties.  When I was a schoolteacher we acquired a new illustrated book of fungi, and within days the page with the "magic mushroom" had been very neatly removed.  (I am not revealing the real name of this toadstool in case any reader of "Lookaround" should be misguided enough to try eating them, with potentially dire consequences).
  Many toadstools are parasites on plants; in fact I'm sure some readers will have had valued trees or shrubs killed by the dreaded "Honey Fungus".  Others again go into partnership with trees; in fact all of our trees and shrubs benefit from having a mycorrhizal fungus associated with their roots.  The fungus takes up mineral nutrients from the soil and passes them into the tree roots, and the tree responds by sending down food for the fungus and everyone is happy.  Some of these produce fruiting bodies, like the Cep and the Chanterelle, which are even better eating than Field or Horse Mushrooms, while others like the Death Cap are, quite literally, deadly even in small quantities.  (Moral: don't eat any fungus unless you are "dead" certain what it is).
  Mushrooms and toadstools are fascinating and full of surprises, and one or another can be found   at any time of the year, but the fruiting bodies are commonest in late summer and autumn.  Each year there are fungus forays.  These are usually well advertised, so do keep your eyes open and go along to see what an expert can show you.  You might even go home with a (safe) meal in your basket. John Mounsey