A species new to science, Micarea svetlanae, is described from the southern part of the Russian Far East based on morphological, chemical and molecular data. This species is closely related to M. isidioprasina, which also has the micareic acid, the granular-isidiate thallus with Sedifolia-grey pigment, and crystalline granules in the hymenium and thallus, but differs in the cushion-shaped thallus, the presence of Sedifolia-grey pigment in the hymenium, numerous crystalline granules in the hymenium and hypothecium and 0–2(3)-septate ascospores. The results of the phylogenetic reconstruction place M. svetlanae in the M. prasina group. Morphological features and data on ecology, distribution and secondary metabolites are presented in detail in the paper. This new lichen species is named in honour of the Russian lichenologist Dr Svetlana Tchabanenko, who devoted her life to the study of lichens of the Russian Far East.
