Description: English: Depiction of the results of standard chemical spot tests on the foliose lichen Punctelia borreri. The C+ (rose) reaction in the medulla indicates the presence of gyrophoric acid. Date: 9 April 2013. Source: https://mushroomobserver.org/image/show_image/321398?q=1g3OL. Author: Zaca Lepista (zaca).
Description: English: Results of chemical spot tests on the foliose lichen Punctelia borreri showing thallus (top) and medulla (bottom). Specimen found in the Parque de Monsanto, Lisboa, Portugal. Date: 3 June 2011. Source: https://mushroomobserver.org/image/show_image/149849?obs=68690&q=1jLlT. Author: zaca.