Usnea (Usnea lapponcia) is a wispy little lichen that doesn’t look like much but in the medical lab, it has demonstrated its strength! Usnic acid, the main constituent of Usnea, has been extensively studied as an antibiotic that inhibits 16 known gram-positive bacteria (both the resistant and non-resistant strains) including streptococcus, staphylococcus, and mycobacteria. Usnea […]