Seinääliikkiin

Seinääliikkiin is a Finnish term that translates loosely to "wall lichen" or "lichen on a wall." It refers to a variety of lichen species that commonly grow on vertical surfaces, particularly on man-made structures like stone walls, concrete, brick, and sometimes even painted surfaces. These lichens are a symbiotic organism consisting of a fungus and an alga or cyanobacterium.

The presence of seinääliikkiin is a natural phenomenon and indicates a stable environment with sufficient moisture and light. Different species of seinääliikkiin have varying tolerances to pollution and substrate types. Some are more sensitive to air quality, making them potential bioindicators. Common types found on walls include crustose lichens, which form a crust-like growth directly on the surface, and foliose lichens, which have leaf-like lobes.

While often seen as decorative or a sign of age, seinääliikkiin can sometimes affect the structural integrity of the substrate over long periods, especially in damp conditions where it can retain moisture. However, for most historical and modern building materials, it poses no significant threat. Removal is generally not necessary unless there are specific aesthetic concerns or if the lichen is contributing to moisture-related damage, though chemical removal can be harmful to the lichen itself and potentially the substrate.