Corticolous crustose lichens in Pangasinan, Philippines, including one new country record

Corticolous crustose lichens are one of the understudied groups of lichens in the Philippines due to the limited research and insufficient taxonomical knowledge among these taxa. This study extends the inventory of corticolous crustose lichens in western Pangasinan, Philippines, specifically in Alaminos city tree park, an area established in local reforestation efforts. Morphological, anatomical, and chemical characterizations were done to identify the lichen species. Character and character states of the ascomata, hymenium, exciple, ascus, ascospore, and lichenic acid were examined. Moreover, a provisional dichotomous key was created. This survey identified ten lichen species across five families. The crustose families were Arthoniaceae, Coenogoniaceae, Graphidaceae, Malmideaceae, and Trypetheliaceae. The species identified were Coniocarpon cinnabarinum, Coenogonium geralense, Carbacanthographis albolirellata, Diorygma confluens, Graphis furcata, Graphis lineola, Malmidea subgranifera, Nigrovothelium inspersotropicum, Sarcographa labyrinthica, and Trypethelium eluteriae. The Graphidaceae family has the highest number, with four species, followed by Trypetheliaceae, with two species. The Arthoniaceae, Coenogoniaceae, and Malmidaceae families have only lichen species each. Notably, Carbacanthographis albolirellata represents a new distribution record for the Philippines. The richness of corticolous crustose lichen species in Alaminos City Tree Park is relatively low. Nevertheless, the one newly recorded species in the Philippines added valuable insights to the limited lichen research.