Royal Mycologic Gardens, Kew

There's a rare and unusual fungus fruiting in Kew Gardens. It's not pretty, but its pretty interesting. More on that later.

The latest edition of Kew Magazine features fungi. There's an interview with Brian Spooner who is retiring after 36 years at Kew, and another of our fungal experts (another mycologist) Martyn Ainsworth illustrates and writes about some of the showy fungi growing in Kew Gardens - things like mushrooms, toadstools, bracket fungi and the like.

Martyn starts out by reminding us there are 1.25 million fungi in the 'Fungarium', Kew's collection of preserved fungi complementing the 6 million strong Herbarium. There are less fungi living in Kew of course but Martyn estimates around 2,750, including lichens (which are fungi closely associated with algae). This is more fungi than there are native plants and ferns in the whole British Isles (2100)!

Fungi statistics are like that - big. We don't know how many fungi there are in the whole of the United Kingdom but it's thought to be about six to seven times as many as the number of flowering plants. But this may be way off the mark, up or down. Brian Spooner reckons more than 90 per cent of fungi alive on Earth today are yet to be described!

Although Kew has been a rich collecting ground for mycologists, only three species names celebrate this regal location with 'kewensis'. There have been some memorable finds though. For a while Kew held the record for the largest reported fruiting body in the world - but see my recent posting on a new record breaker.

The one that grabbed Martyn's attention this week was this one, Podoscypha multizonata. One of our horticultural staff pointed it out to Alick Henrici, a volunteer mycologist at Kew. Martyn describes the fungus in an email to me as a  "zoned rosette which fruits on buried roots (probably dead or weakened but exact trophic status not known) of Fagaceae (usually Quercus or Fagus)".

Martyn says most of the world's population of this species grow in England and France, with quite a few near to London, such as Richmond Park, Windsor Great Park and particularly in New Forest. However it's thought to be in need of protection and care across its range, and is listed on 'Section 41' of the Natural Environment Research Council (NERC) meaning it's an important part of England's biodiversity.

The specimen fruiting in Kew Gardens is particularly curious because it's growing on the roots of an Ash (Fraxinus excelsior), the first time this has been recorded in the UK.

The fruit body is long-lasting and Martyn says it will persist for maybe a few months or longer, although gradually turning black.

Although it's been found in Kew before this is the first time we've been able to document it properly and it's the only one seen this year. We'll look at a wee fence to protect it - from accidental damage from visitors and mowers - and hopefully put up a little sign to celebrate it's appearance. 

In the longer term, we'll have to think about what happens to the tree at the end of its 'useful life' - in this case it may remain very useful in its decline, or even as a stump. As Martyn puts it we don't want to "leave the fungus homeless and hungry". Indeed.