Fungi benefit from autumnal weather

As I write this a monsoon-like shower of rain is hammering on our living room window, a frequent occurrence over the last few weeks. You'd be forgiven for thinking that we are somewhere in the middle of October. But at least it's perfect weather for fungi, some of which are now fruiting conspicuously in our forests. During the SEWBReC meeting at the large and biodiverse Maerdy coal tip last Saturday, several recorders noted impressive populations of  Suillus viscidus and Gomphidius maculatus associated with Larch. I hope the Maerdy Larch plantation will escape felling so that these populations can survive.

Suillus viscidus (Resolven)

Gomphidius maculatus (Maerdy)

Closer to home, Suillus viscidus was also fruiting in similar Larch plantations on old coal tips at Resolven and Dyffryn Cellwen. Lots of common species such as Clavulina rugosa, Laccaria laccata, Gymnopus dryophilus (= Collybia dryophila), Mycena rorida, Mycena sanguinolenta, Mycena stylobates, Mycena leptocephala,  Suillus grevillei and Suillus luteus were abundant, but less recorded species such as Gymnopus aquosus and Otidea onotica were also there.

Gymnopus dryophilus and Mycena sanguinolenta (Resolven)

Suillus luteus (Dyffryn Cellwen)

Gymnopus aquosus (Ton Mawr) - note bulbous base to stipe

Otidea onotica (Dyffryn Cellwen)

There were some nice patches of Rhodocollybia prolixa under the Larch in Dyffryn Cellwen. This is an uncommon species in Britain, new to me, but I see from the NBN database that it has been recorded previously in South Wales. Illustrations (and photos) of this species are a bit misleading in some of the guides, but there are some nice images on the web. However, the taxonomy of this species is also confusing. Firstly, lots of guides use the outdated name of Collybia, now largely replaced by Gymnopus and Rhodocollybia. Secondly, several guides describe two species, Collybia distorta and Collybia prolixa, which have been very difficult to separate, the main difference between them being the size of the basidiospores. The spores of distorta are very small (3-4 microns) while those of prolixa are larger (4-6 microns). The Dyffryn Cellwen population has very small spores (mean 3.5 microns), so I am recording this as Rhodocollybia prolixa var. distorta (= Collybia distorta).

Rhodocollybia prolixa var. distorta (Dyffryn Cellwen)