lichens

Greens, grays and browns on the rocks had me fooled during childhood. I was certain the rough, scaly looking stuff on boulders was the result of prehistoric creatures rubbing against the rocks and leaving scales behind. I couldn't understand how anyone thought dinosaurs never existed as there was "proof" all over the countryside, with actual green and gray scales in abundance for anyone to see. Somewhere along the years that childhood belief was forgotten and knowledge of lichens was acquired, the memory faded away, forgotten until my own offspring came along and asked me what all the colorful stuff on the rocks was.



Lichens are small plants that cling to surfaces such as rocks and trees, and they grow throughout much of the world. They are really two plants growing together in a symbiotic relationship, an algae and a fungus. If you know a little about plants, you probably know that fungi are decomposers and do not make their own food, but find nutrients through the decomposition of other plants and animals. Algae, on the other hand perform that amazing process of photosynthesis, where sunlight is converted into food. In a lichen, the two plant types work together with each performing different roles in maintaining life. Lichens are slow growing, and tend to grow in places that are very inhospitable to other types of plants, such as on the surface of rocks or on tree bark.

The colorful rock in this image is covered with a variety of lichens, large "leafed" brown, some sort of gray with visible "leaves" and a scalier, greenish yellow lichen of almost a neon yellow hue. In springtime, when rains are abundant, lichens plump up and become soft and springy. By the end of summer they dry out and become hard.