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-like Tillandsia').
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.
Usnea is very sensitive to air pollution, especially sulfur dioxide. Under bad conditions they may grow no larger than a few millimetres, if they survive at all. Where the air is unpolluted, they can grow to 10-20 cm long.
Usnea has been used medicinally for at least 1000 years. Usnic acid (C18H16O7), a potent antibiotic and antifungal agent is found in most species. This, combined with the hairlike structure of the lichen, means that Usnea lent itself well to treating surface wounds when sterile gauze and modern antibiotics were unavailable. It is also edible and high in vitamin C.
Native Americans employed it as a compress to severe battle wounds to prevent infection and gangrene, and it was also taken internally to fight infections. Usnea contains potent antibiotics which can halt infection and are broad spectrum and effective against all gram-positive and tuberculosis bacterial species. Usnea has several unique characteristics which make its identification easy if stranded in the wilderness far from a hospital. Usnea lichens can be easily identified by pulling back the outer sheath on the main stem. Usnea lichens have an elastic pure white chord running through the center of the main stem. Lichen species which resemble Usnea do not have this white cord, and appear grey-green throughout. Usnea lichens do not change color throughout the growing season as do lichen species which closely resemble Usnea.
Ah, I see my beard right there hanging from the branches of a tree, Subhash :).
These lichens and mosses are truly amazing; I have seen some with my own eyes in the Himalayas.
You have captured them very well in this picture.
The note on them is very informative.
Thanks and regards.
What an amazing sight! These lichens look like they are hanging out to dry. You have captured them well with good details and textures. They stand out so nicely against the dark greens surrounding them.
Hi Subhash,i never seen nothing like that,another great surprise from your country! You choose the best light position to a great result in sharpness and details like that.Thanks to show this unknown crazy of nature.Have a nice weekend,LUCIANO