The Ashen Knight (Tricholoma virgatum) is an attractive species with a shiny, grey, fibrous cap. Although it is often described as a species of deciduous woodland, it often grows with Spruces and Pines in our plantations.
There is a large area of pine plantation on Foel Fynyddau (the hill above Pontrhydyfen and Cwmafan), where you can find Macedonian Pine (Pinus peuce), Scots Pine (Pinus sylverstris subsp. sylvestris) and Lodgepole Pine (Pinus contorta). With such a large area of pine forest you might expect to find some nice pinewood species. The best is undoubtedly Yellow Knight (Tricholoma equestre) which is also called Man-on-horseback (for reasons unknown to me!).
Yellow Knight is a really interesting species. In Britain it is mostly known as a species of Scottish pinewoods and it appears to be very rare in southern Britain, so its occurrence in the pine plantation on Foel Fynyddau is notable. It is sometimes recommended as an edible species, but recently there have been a number of serious poisoning incidents associated with it and it also seems to accumulate mercury under certain conditions. Perhaps these two things are related.