Scientists have found a clue to the rare phenomenon of "ice hair"

If the temperature in winter hovers around zero degrees, the humidity is high and the observer is between 45 and 55 degrees north latitude, in the middle of the forest, he has a chance to encounter an unusual phenomenon called "ice hair". These are thin strands or strands of ice that grow on fallen trees. The spectacle is very unusual and really resembles an attempt to create pile or wool from ice, although it is based on completely different processes.

For a long time it was believed that this is just another, very complex form of frozen water, until in 2015 scientists discovered what they called a "recrystallization inhibitor." Its source is the mushroom Exidiopsis effusa, which settles on dead or dying trees. It is the activity of the fungus that forms thin ice threads, but how does this happen?

Strictly speaking, the exact mechanism is still unknown. Previously, it was believed that a freezing tree releases sap, which freezes into threads, but now it has been established that this fungus destroys the wood, and the liquid protruding to the surface is a by-product. In contact with cold air, it freezes with an ice crystal, but since the flow presses from below, the crystals are piled up on top of each other, forming a thread. Its thickness is only 0.01 mm with a length of up to 20 cm, but why do these thin and fragile structures not break?

It turned out that in addition to water, the fungus extracts lingin and tannin from cellulose and throws it out. When they come into contact with water in the cold, they become a kind of glue that strengthens the threads. And they probably interfere with the formation of large fragments of ice, forcing the filaments to grow apart, without mixing. Now scientists have to test their hypothesis with observations in wildlife.