CDB273's picture

HoLIDAY 2012 DEVON 072

Observed: 7th September 2012 By: CDB273
S159 Neighbourhood Nature - current student
hoLIDAY 2012 DEVON 072

Caution: Do NOT use iSpot to identify fungi to eat!

Some fungi are very poisonous so a mistaken ID could have serious consequences.

  • Crustose Lichen
    Confidence: I'm as sure as I can be.
Species interactions

No interactions present.


fungi's picture

and foliose lichen in yellow patches

Some (perhaps not all) of the whitish-greyish cover on the trees is probably formed by crustose lichens, however, the orange patches are from a foliose (leaf-like) lichen. It's a Xanthoria species. In some patches, in particular the uppermost right one, it can be seen that the lichen is not with its total undersurface closely attached to the bark, but 'peeling off'.

AlanS's picture

Xanthoria etc.

Agreed that the obvious yellow patches are a Xanthoria. I see from the associated vegetation that this is at the top of a saltmarsh, and much the most likely species on a standing trunk and dead wood in this situation would be X. parietina. However the surface features are not distinct enough in the photograph to confirm this.

This is the sort of habitat that X. parietina has always occupied, where it benefitted from nitrates being deposited as a result of drift in the wind from sea-spray. In modern times it has become very common inland as a result of other types of nitrogen deposition, from agrochemicals and vehicle exhausts. It has also a long history of being on farm buildings as a result of organic nitrogen/ammonia deposition - I was interested to note a reference to yellow lichen on farm buildings in a Sherlock Holmes story, written over 100 years ago of course.

Out of curiosity I have blown up the photograph in Photoshop, and while much of the grey on the trunk might be a crustose lichen (close examination with a hand-lens needed), the only crustose lichen I am sure of is near the top of the photograph, where there are some immature thalli developing on the trunk.

There are small, grey clumps of a Physcia species (P. tenella or P. adscendens, cannot tell from the photograph) and these are also foliose. Near the top of the photograph are greenish patches of a Melanelixia species, again foliose.

I like this photo, but in truth it is not the best to demonstrate crustose lichens.