Knudsen, K., J. C. Lendemer & R. C. Harris 2011: Studies in lichens and lichenicolous fungi -- no. 15: miscellaneous notes on species from eastern North America. - Opuscula Philolichenum9: 45-75. [RLL List # 223 / Rec.# 32902] Abstract: Acarospora americana is revised and separated from A. veronensis. Acarospora superfusa and A. cinereoalba are placed in synonymy with A. americana. A lectotype is selected for A. cinereoalba. A key to the Acarospora species from North America with gyrophoric/lecanoric acid is presented. Acarospora gallica, A. rugulosa, A. sparsa, A. tongleti, and A. variegata are excluded from the North American lichen biota. Range extensions are reported for A. janae, A. nicolai, and Sarcogyne reebiae. The name Arthonia subcyrtodes is placed in synonymy with A. intervienens. The combination Bactrospora carolinensis (for Patellaria carolinensis) is proposed and B. mesospora is placed in synonymy. The following taxa are described as new to science: Acarospora piedmontensis (from the Piedmont of southeastern North America), A. sphaerosperma (from the Ozarks and Ohio), Lecanora zeroensis (from the Coastal Plain of Georgia), and Melanophloea americana (from the Mid-Atlantic Region). Polysporina cyclocarpa is newly reported from continental North America. Xanthomendoza weberi is revised to include X. rosmarieae and Xanthoria wetmorei as synonyms.