Evernic acid is an organic compound and depside with the molecular formula C<sub>17</sub>H<sub>16</sub>O<sub>7</sub>. Evernic acid was first isolated from the lichen Usnea longissima. Evernic acid is soluble in hot alcohol and poorly soluble in water. Evernic acid is produced by the lichens Ramalina, Evernia, and Hypogymnia.