People passing through Blaxhall Heath this year may have seen beside the road the huge pile of woodchips from the heathland restoration work taking place. Those with a keen eye may even have noticed a regular crop of fungi growing on this pile, a fungus they had never seen before and were unable to identify.

In 2003, a fungus new to science was found growing in a pile of sycamore woodchips in the Netherlands. It was named Agrocybe rivulosa. Soon it was turning up in other parts of the continent.

By 2004, two records were made in the UK, and it is now widespread throughout the land.

It is thought that imported material containing ‘spawn’ might be responsible for its introduction here, but it is now known that British-grown woodchips sold in garden centres are responsible for its spread all over the UK.

I first found the species in Suffolk a few years ago, growing in the raised flower borders of Wild about Birds at Theberton, but I was unable to name it simply because nothing had been written about it at the time. Berry’s of Framlingham had supplied the woodchips on the border, and I was able to find out that poplar was the main material, whereas at Blaxhall the woodchips would be Betula and Pinus spp. A. rivulosa is recognised by its comparably large size for an Agrocybe species, with a normally wavy (rivulose) cap surface and a very long hanging ring around the top half of the stem which becomes broken up as the fungi matures.
It’s probably coming to a woodchip pile near you soon…

Neil Mahler