"Lichenes" from Ernst Haeckel’s Artforms of Nature, 1904
Lichens are composite organisms consisting of a fungus and a photosynthetic partner growing together in a symbiotic relationship. Many lichens reproduce asexually, either by vegetative reproduction or through the dispersal of diaspores containing algal and fungal cells.
Lichens must compete with plants for access to sunlight, but because of their small size and slow growth, they thrive in places where higher plants have difficulty growing. Lichens do not have roots and do not need to tap continuous reservoirs of water like most higher plants, thus they can grow in locations impossible for most plants, such as bare rock, sterile soil or sand, and various artificial structures such as walls, roofs and monuments.
Lichens are widespread and may be long-lived; however, many are also vulnerable to environmental disturbance, and may be useful to scientists in assessing the effects of air pollution, ozone depletion, and metal contamination. Lichens have also been used in making dyes and perfumes, as well as in traditional medicines. Much more - http://en.m.wikipedia.org/wiki/Lichen
Photograph by David Doubilet, National Geographic
Arctic Fox - Svalbard, Norway by Rune Almeland
It hurts every day, the absence of someone who was once there.
— Marie Lu
Toteninsel (2009) - Harry Kaufmann
Forest in the Lao Highlands (by daniel.frauchiger)