Thursday, April 07, 2011

U - Usnea





U - Usnea

The letter U certainly was a challenge. In fact, I had to go through a list of words beginning with that letter. When I came across the definition of Usnea in Wikipedia (see below), I realized that I had photos to share.

Usnea is the generic and scientific name for several species of lichen in the family Parmeliaceae, that generally grow hanging from tree branches, resembling grey or greenish hair. It is sometimes referred to commonly as Old Man's Beard, Beard Lichen, or Treemoss. Usnea looks very similar to Spanish moss, so much so that the latter plant's Latin name is derived from it (Tillandsia usneoides, the 'Usnea-likeTillandsia').

Usnea grows all over the world. Like other lichens it is a symbiosis of a fungus and an alga. The fungus belongs to the division Ascomycota, while the alga is a member of the division Chlorophyta.

I am amazed by a type of life that has adapted to a variety of environments all over the planet and survives by hanging from tree branches. I have photographed old man's beard in all seasons in a variety of lighting situations and will probably continue to make images wherever I see this lichen growing.

Photos of the Day are for sale as stock photographs
and photographic enlargements.
They can also be purchased as slide shows
and/or wallpapers/screensavers.


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