«FOLIA CRYPTOGAMICA PETROPOLITANA» (ISSN 1810-9586) – a book series; scientific publication of a non-strict periodicity. It has been published since 2004. The name and initial idea of the series imply the publication of materials on taxonomy, biodiversity and ecology of fungi, algae, lichens and bryophytes, exceeding the limits of a scientific paper in volume terms. To date, the series has seven monographs.