The Mysterious Patches on the Wood

A fallen branch lay beside the woodland path. Grey-green patches with fine, crinkled edges grew on its bark. Puschel stopped. He looked at the branch and then at his own paws, as though checking for paint.

Puschel“Someone has painted the woods. Very neatly, but the colour is rather pale.”

Flauschi crouched down. She held the green magnifying glass over a patch without lifting the branch. Puschel leaned towards the branch from the other side. The edge looked like tiny flat frills. He did not rub a paw over it.

Flauschi“That looks like a lichen. Lichens are neither painted patches nor cushions of moss.”

Puschel“Is it a plant with a very flat hat, then?”

Flauschi“Different living things live closely together in a lichen. A fungus is a kind of living thing; mushrooms belong to this group. In a lichen, a fungus is usually joined with tiny algae. Algae are living things, and many can use light to make sugar.”

Puschel studied the patch again. Flauschi explained that the fungus helped build the lichen’s body. It sheltered the algae and helped supply water. The algae made sugar with light, and the fungus received some too.

Puschel“A shared home with a shared food cupboard. Who does the washing-up?”

Flauschi laughed. Of course, there were no plates or kitchen inside. Such a close living partnership was called symbiosis. Their ordinary magnifying glass could not show the tiny partners separately.

Flauschi“We can see the lichen. We cannot see its fine inside structure this way. We do not know its exact kind yet either.”

Puschel“Then the colour stays on. We do not need to scrape it off to be curious.”

Flauschi lowered the magnifying glass. The fallen branch stayed where it lay. As they walked on, Puschel noticed another patch on some bark. This time he did not call for a painter. First he simply looked more closely.