Beard lichen, Usnea

ChHsOs, Mr 272.21, orange platelets that decompose above 250 °C with KOH they give a dirty-green color and with Mg(OAc)2 a red-violet color, soluble in acetone. A naphthoquinone from the beard lichen Usnea canariensis indigenous to the Canary Islands. 

Commonly called old man s beard, a name derived from its appearance, usnea is a lichen that grows on living and dead trees throughout the world. It is quite common in North America, and this wide availability and its strong antibacterial properties make it a significant herb in treating resistant bacteria. 

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