The genus Humidophila (Bacillariophyta) in Greenland with the description of 2 new species

During a survey of the terrestrial moss diatom flora in Greenland, two unknown Humidophila species were observed that could not be identified using the currently available literature. Detailed morphological analysis using both light and scanning electron microscopy revealed sufficient morphological differentiation from known species to describe these as new species: H. helderiana sp. nov and H. mitosis sp. nov. Formal descriptions are presented, each illustrated by light and scanning electron micrographs, and the new species are compared with similar Humidophila taxa worldwide. Additionally, eight previously described species which were also observed are discussed, and Humidophila mochalovae comb. nov., formerly belonging to the genus Diadesmis, was transferred to Humidophila. Of these known species, six have not been previously reported from Greenland, expanding their known geographic distributions. Our findings bring the total number of Humidophila species globally to 87 and contribute to a better understanding of the terrestrial Arctic diatom flora.