Species of the Month - October 2016

Blackening Waxcap

Hygrocybe conica
 

October is the peak season for waxcaps, specialist fungi of unfertilised grasslands in which LNHG has a particular interest.  Blackening Waxcap is one of the commonest species, with a wider habitat range than most of the others.  As well as grasslands it can occur in dunes, marshes, bogs, woods, heaths and riverbanks (Boertmann 1995).  It turns black with age or when damaged or bruised, which makes it easy to distinguish from other kinds of waxcap.
 

When fresh it has a conical cap with radial fibres, rather sticky at first but soon dry.  The colours are usually yellow, orange, red, or some mix of these.  The stem is yellow or orange and beautifully translucent when young, smooth with vertical veins.  The gills are whitish at first, becoming yellow or orange.  They curve up before reaching the stem and often stop short of reaching it at all, an unusual feature in a waxcap.  Most other waxcaps with the gills ascending still have them firmly attached to the stem.
 

If found before it has begun to blacken, it could be mistaken for the Persistent Waxcap (H persistens or H autoconica) but the Blackening Waxcap can always be made to blacken by bruising it and then waiting a while.
 

This one has begun to turn black on the stem and at the top of the cap.  The stem becomes more fibrous with age.
 

More waxcaps in the process of blackening.  The cap often turns brown before it turns black.
 

Finally one with the whole cap black, and another that has turned black completely.

The Blackening Waxcap is very variable, with a number of forms associated with different habitats.  In the past it was split into 2 or 3 different species, so if you have an old mushroom book it may show more than one waxcap as turning black.  However the current authorities regard all these as forms of a single species, Hygrocybe conica.

This situation is too good to last, and it is likely that DNA testing will result in the species being split again, so make the most if it while you can!  If you take photos of your waxcap and note its habitat then it may well be possible to attribute your record to one of the post-split species when these are finalised.  If not, the record is still of value as H conica counts along with all other waxcaps in assessing the conservation value of grasslands.


Please send in your Blackening Waxcap sightings using the form below, or email sightings@lnhg.org.uk with the details if you prefer.  If you are not sure of the identity of your fungus, please send a photo to sightings@lnhg.org.uk, or put one on the LNHG Facebook page.