The rare Hazel Gloves fungus

Hazel Gloves -  Hypocreopsis rhododendri

So here I am, photographing a group of Early Purple Orchids which I monitor each year, and as I am about to walk away I look across to see what I at first assumed to be Curtain Crust fungus growing on a branch of an old Hazel. Something told me to go a little closer and I'm glad I follow my instincts sometimes, because when I looked closer I could immediately see this was something different.

I was certain there and then what this was and my heart was racing. This was a lifer for me and I was tempted to put a tweet message out there and then saying what I had found, but I just wanted to be that 100% sure. I emailed Pat O' Reilly, author of Fascinated by Fungi, and he confirmed what I had found - I knew it.  To say I was very excited would be underestimating how I felt.

So what are Hazel Gloves?

They are a rare fungus, and in Britain it occurs only on old Hazel trees, often in ancient coppice woodland. The finger-like stromata of Hypocreopsis rhododendri are the origin of its common name Hazel Gloves. The 'Hazel' part of the name refers to the tree species upon which this fungus is found in Britain and Europe, and not to the nut-coloured fingers themselves.

Distribution

In the UK it is a rare find, so you can understand my excitement when I realised what I was had found, Hazel Gloves fungus occurs also in parts of mainland Europe as well as in North America, where it was first described scientifically from the Appalachian Mountains of the eastern USA.

The fungus was first described scientifically in 1922 by American mycologist Roland Thaxter (1858 - 1932).

The genus name hypocreopsis comes from hypo- meaning under and -creopsis which may imply 'similar to snakes' - and if so it is probably a reference to the contorted fingers of the stromata of Hazel Gloves.

These striking fungi vary in colour from pale orange through to tan and to a very deep orange. Stromata can be up to 20cm across, with individual finger typically 1 to 2cm across and up to 10cm long. When mature, the central area of a stroma becomes brown Perithecia (flasks inside which ascospores ripen) embedded in the stroma become visible. Although found on old hardwood trees - (Hazel in Britain) - this species is believed to be parasitic on Glue Crust fungus Hymenochaete corrugata. It is not always possible to see the host fungus, which may be covered by Hazel Gloves and by mosses, and I certainly couldn't anything else associated with this fungus.

Season

These long-lasting fruit bodies are usually at their best from August to the end of December in Britain and Ireland, but old blackening fruit bodies are often in evidence right through to the following summer, when new Hazel Gloves begin to appear - which explains why I found these in April.

Similar species

Hazel Gloves is unlikely to be confused with any other British fungus except the almost-identical Willow Gloves Hypocreopsis lichenoides - even rarer in Britain - which usually has a darker brown stroma and grows mainly on Willows. Although having a black outer surface rather than fawn or tan, Dead Man's Fingers Xylaria polymorpha is similar in size and shape to Hazel Gloves; it grows mainly on dead hardwood timber under the ground and is most often seen around the bases of rotting beech stumps.  I am familiar with Dead Man's Fingers and in my opinion the two are not similar. 

After putting the pictures out on Twitter, I felt proud of the response by other people, with over 500 likes and several hundred -re-tweets, and my thanks go out to everyone who took the time to comment and re-post this rare and characteristic new fungus for me.