The genus Phaeomegaceros is characterized by yellow spores with distal fovea, stomata in the capsule wall, pyrenoidless plastids and typically monandrous androecia. Based on morphology and sequence data we transfer Phaeoceros squamuligerus (Spruce) Hässel to the genus
Phaeomegaceros and describe a new subspecies, P. squamuliger subsp. hasselii, from Osorno, Chile. The distinguishing features of this new subspecies are: a smooth broad thallus, robust sporophytes (up to 0.7 mm thick in transverse section), large yellow spores (45–60
μm in diameter) with a central deep depression and regular ridges around the periphery of the distal face. The main differences between this subspecies and the typical P. squamuliger is the absence of dorsal outgrowths and the presence of pronounced ridges surrounding the central
depression on the distal face of the spores. Morphological comparisons with other species of the genus are made. Based on current data, Phaeoceros chiloensis and Phaeoceros foveatus are also transferred to Phaeomegaceros.
Nova Hedwigia is an international journal publishing original, peer-reviewed papers on current issues of taxonomy, morphology, ultrastructure and ecology of all groups of cryptogamic plants, including cyanophytes/cyanobacteria and fungi. The half-tone plates in Nova Hedwigia are known for their high quality, which makes them especially suitable for the reproduction of photomicrographs and scanning and transmission electron micrographs.