Friday, 12 February 2016

Physcia tenella - Fringed Rosette Lichen


 Learn your lichens 7.
The Physcia is the teeny weeny grey foliose lichen covering the trunk in the bottom two thirds of the picture on the left. (The large grey foliose lichen is a Parmelia (saxatile or sulcata) - I'll write about that another day)

You are probably more likely to find Physcia on a tree in Settle than any other species of lichen.  If you can see a big yellow Xanthoria have a look nearby for Physcia.  Tenella means delicate.

Learn your Lichens Series
1. Arthonia radiata
6. Lecanora gangaleoides
7. Physcia tenella

The ruler on the left shows centimetres
divided into millimetres. Look more closely..



This one is fruiting. You can see the black discs. 

This species of Physcia has cilia ("hair-like projections"), sometimes with black tips growing from the undersurface.
I photographed this through my hand-lens. See the cilia
The thallus has gone pinkish because it is infected by a fungus



The top picture is of Physcia tenella on this Mountain Ash at Langcliffe, but there are at least 12 other species of (mostly bigger) lichens on it too - a fantastic tree.
....and five mosses
.... and two liverworts.
I photographed the other pictures on the nearest tree here in Malham YDNP car park several years ago, ready for my Algae and Lichens of Malhamdale walk.
  






The etips of the thallus are curled up at the top right of the picture and the undersurface of the tips are covered with powdery soredia. You can see the cilia clearly here.  this picture was taken on an oak branch in Grinton churchyard

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