I have been thinking about starting this thread for a while, and have been spurred into action by Lancashire Lad's post about rust on Dog Rose.
Unfortunately that is a case where (as so often in the study of fungi) one needs access to a microscope. However, the good news is that when it comes to groups such as the rusts, smuts, powdery and downy mildews etc. this is often not the case - in fact a much higher proportion can be confidently named to species without microscopic examination than is the case with agarics, brackets and the like.
All one needs is a good botanical knowledge and a handlens. Someone like KeenTeen would be perfectly equipped to make exciting discoveries, and I know there are many WABbers who know their British plants very well. In addition it adds another string to ones mycological (and indeed botanical) bow when you are out and about. A lot of these parasites are most successful when their hosts are stressed, and patches of waste ground in the middle of towns and cities can turn up very interesting finds.
I am kicking off here with a rust on Pignut which I found yesterday. on checking the records it appears to be rare, but that might well be because not a lot of people are aware of such things. There are two rusts on this host, this aecial 'cluster-cup' stage and another one which doesn't distort the host in this way and has chocolate coloured spores Puccinia tumida
In the strange way of things this species, Puccinia bistortae also
has a chocolate coloured stage but on a completely unrelated host - Common Bistort. Sometimes the two species can be found on the same leaf, and it was through the experimental work of a late 19th century amateur Yorkshire mycologist, Henry Thomas Soppitt, that the true picture emerged - the logical thought being that the rusts on the Pignut must be one thing and that on the Bistort another.
Trust me, in general the picture is much more straightforward. If someone says to me "I have seen the chocolate rust on Bistort" I know exactly what they mean and can give them the species name.
I shall regularly post here on this thread and will make sure that what I post is what is around at the time (at least in Yorkshire and that is fairly central in British terms). I'll try to give hints on identification, things to look out for etc. and will in general not include anything which cannot be identified in the field. I'll happily look at anything people have photographed/collected and do my best to name them (a useful hint is that these fungi scan well and that is sometimes by far the easiest way to 'photograph' them). I will put all the species I post on the A to Z
Finally I promise that in future I shall not ramble on at this length
- this should be thought of as less of a ramble than a preamble.