Current Lichen Research in Indonesia: Diversity, Taxonomic Gaps, and Future Perspectives

Abstract

Indonesia is one of the world’s biodiversity hotspots, yet its lichen diversity remains understudied compared to vascular plants. This review compiles current knowledge on the taxonomy, morphology, anatomy, and distribution of lichens across major Indonesian islands. A total of 317 species with valid binomial names have been documented, dominated by the families Parmeliaceae and Graphidaceae, with crustose thalli being the most common form. Java and Sumatra show the highest diversity due to more intensive fieldwork, while records from Eastern Indonesia, such as Papua and Moluccas, remain limited but indicating considerable potential for further discoveries. Species identifications were validated from peer-reviewed publications and checked against updated taxonomic references to reduce synonymy and misapplication. Most studies have relied primarily on morphological and anatomical features, such as thallus type and spores, while molecular and chemical analyses are still limited although they are already applied in some recent works. Lichens in Indonesia play important ecological roles as pioneer species, nutrient recyclers, and sensitive bioindicators, while also providing bioactive metabolites with medicinal potential. This review highlights the importance of integrative taxonomic approaches combining morphology, anatomy, chemistry, and molecular tools, together with expanded field exploration, to better document Indonesia’s lichen diversity also to strengthen their application in biodiversity conservation and ecological monitoring.