CRITICAL NOTES ON ANTARCTIC YELLOW ACAROSPORACEAE

All species of Antarctic Acarosporaceae (s. lat., including Biatorella ceae) with yellow thalli are revised. Four genera, Acarospora, Biatore lla, Biatorellopsis, Eklundia, and ten species, all of them endemic, w ere previously reported from Antarctica. Our results indicate that in Antarctica Acarospora subgen. Xanthothallia s. str. includes only two species, A. gwynnii Dodge and A. flavocordia sp. nov.; Biatorella does not occur in Antarctica, the species described by Dodge belonging ins tead in Candelariella; the genus Eklundia is a synonym of Candelariell a; Biatorellopsis does not occur in Continental Antarctica, and the ge nus is a synonym of Pleopsidium; Pleopsidium is represented in Antarct ica by one species, P. chlorophanum, which was treated under very diff erent generic and specific names by earlier authors. Altogether, the n umber of species of yellow Acarosporaceae known from Antarctica is red uced from ten to three, distributed in two genera: Acarospora and Pleo psidium. The two Acarospora species, A. gwynnii and A.flavocordia are apparently endemic to Antarctica, whereas P. chlorophanum is a widespr ead bipolar lichen. A comprehensive list of synonyms and a key are pro vided.