Lobaria pulmonaria --- the "Lung Lichen", Part 1

[ralfwagner]

Hello,

the foliose lichen Lobaria pulmonaria forms dens bunchs on dead trunks, preferably on sycamoe maple (Acer pseudoplatanus).



The thallus of a foliose lichen is, as the name suggests, similar constructed to the leaf of a tree. There is a clear differentiation between top and bottom of the leaf. Under a thin cortex of fungal tissue the symbiontic algae concentrate at the top side. A pith consisting of mycelium follows beneath. This pith is terminated at the bottom by a cortex of dense mycelium.



Non-sexual reproduction happens via soralias. These are break-ups at the top side. Here little balls, the soredias, are formed. A soredium consits of algae, wrapped in threads of fungus. It can be recognized as a very small lichen. The reproduction happens by spreading of the soredias to new locations.




Don't forget to have a look at part 2!

[Charles Krebs]

Ralf,
These are extremely common in the forests I enjoy here. But I've never looked anywhere near as closely as you have in these two posts! The sections are great to look at.

I think this came up once before... are these made with a simple hand microtome, or something more elaborate?

[ralfwagner]

Ralf,
These are extremely common in the forests I enjoy here. But I've never looked anywhere near as closely as you have in these two posts! The sections are great to look at.

I think this came up once before... are these made with a simple hand microtome, or something more elaborate?

Charles,

I found it difficult to cut lichens and mosses in a hand-microtome and so I cut them now without. Just with a razor blade in my right hand and the lichen (immersed in drop of water) pressed to a slide with my left forefinger. The forefinger is used also as a "guideway" for the blade. All this is carried out under the stereomicroscope, 5x to 10x magnification. Sometimes, e. g. with small mosses, it is useful to put the moss on a slide, immerse it in a drop of a 20 % solution of PEG 1500 (Polyethylenglycol, Histowax), and wait until all the water is evaporated. The PEG 1500 fixes the moss ancillary on the slide. Then the sections are put in water and the remaining PEG 1500 will be completely dissolved by the water.

It is fine that Lobaria is very common in your area. This means, that the air you breath is clean. Lobaria pulmonaria is known to be very sensitive to air pollution. That is the reason why it is very seldom in Germany. The industries in Germany are very close together, because the country isn't that large. My finding of L. pulmonaria is from a valley in Austria, 1200 m high. In Germany I do not know any location where to find this lichen.

[Charles Krebs]

Ralf,

Your method is simple, and encouraging! I have avoided trying this because I thought it would be necessary to have a more sophisticated microtome and do a lot of work. I'll have to try it.

and the lichen (immersed in drop of water) pressed to a slide with my left forefinger. The forefinger is used also as a "guideway" for the blade.

I'll be sure to have a good supply of band-aids on hand.

The area were I see these in large amounts is the Olympic Rain Forest, on the Washington Coast. This area is right by the Pacific Ocean and as far as the effect on air quality is concerned, the nearest real industrial development is about 4500 miles west over the ocean to Japan!

I suspect you would really enjoy exploring this area. I've posted a few shots of it in these forums here, here, some mushrooms, and even a couple non-microscopic critters!

Charlie