Usnea or Old Mans Beard or Beard Papa
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Usnea is a genus of mostly pale grayish-green fruticose lichens that grow like leafless mini-shrubs or tassels anchored on bark or twigs. The genus is in the family Parmeliaceae. It grows all over the world. Members of the genus are commonly called old man’s beard, or beard papa. It resembles Evernia, which is also called tree moss. Like other lichens it is a symbiosis of a fungus and an alga. In Usnea, the fungus belongs to the division Ascomycota, while the alga is a member of the division Chlorophyta. Members of the genus are similar to those of the genus Alectoria. A distinguishing test is that the branches of Usnea are somewhat elastic, but the branches of Alectoria snap cleanly off.
Dill. ex. Adans. (1763)
Type species: Usnea florida
Like other lichens, Usnea often grows on sick or dying trees due to the pre-existing loss of canopy leaves, allowing for greater photosynthesis by the lichen’s algae; this leads some gardeners to mistakenly blame the lichen for the tree’s leaf loss and illness. 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. It can sometimes be used as a bioindicator, because it tends to only grow in those regions where the air is clean, and of high quality.
According to Paul Bergner, Author of Medical Herbalism. “The usnic acid in Usnea is effective against gram positive bacteria such as Streptococcus and Staphylococcus, making Usnea a valuable addition to herbal formulas for sore throats and skin infections. It is also effective against a bacterium that commonly causes pneumonia Table 19.x shows some conditions that Usnea has been used for in European research.” There is reason to believe that Usnea, in high concentrations, could possess some toxicity. The National Toxicology Program is currently evaluating the issue.
Usnea species have been used to create orange, yellow, green, blue, and purple dyes for textiles.
Usnea barbata has been used in cosmetic production for its antimicrobial and antifungal properties as a preservative and deodorant.
Usnea barbata when dry is extremely flammable and is often used as a firestarter.
Bibliographic details for “Usnea”
Page name: Usnea
Author: Wikipedia contributors
Publisher: Wikipedia, The Free Encyclopedia.
Date of last revision: 19 November 2017 09:24 UTC
Date retrieved: 8 December 2017 22:13 UTC
Permanent link: https://en.wikipedia.org/w/index.php?title=Usnea&oldid=811067368
Primary contributors: Revision history statistics
Page Version ID: 811067368