Algae, lichens and moss often form green or grey, powdery or mossy, crusty growths on the stems, branches and trunks of trees and shrubs. Pictured here, lichen and moss. This dreary "gray all day" ...

Now that deciduous trees are bare, trunks and branches have taken center stage, and you might be noticing nuances and irregularities that evaded your attention over the summer. For instance, what are ...

One of life’s most important symbiotic partnerships may be threatened by a warming climate. Lichens — a composite organism made from cyanobacteria or algae entangled within the body of a fungus — may ...

Those black marks on your patio are a particularly difficult type of lichen that penetrates deeply into surfaces, proving a ...

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Lichen is everywhere. It grows on sidewalks, rocks, trees, roofs and undistributed soil and in frigid tundras, arid deserts and even contaminated environments. You just have to look for it, says ...

You've probably seen a lichen, even if you didn't realize it. If you've ever meandered through the forest and wondered what the crusty stuff on trees or rocks was, they're lichens, a combination of ...

Neil Sperry explains why apparent bark damage may just be harmless lichen, and he answers questions about buffalograss and ...

Lichens -- a combo of fungus and algae -- can grow on bare rocks, so scientists thought that lichens were some of the first organisms to make their way onto land from the water, changing the planet's ...