THE GENUS CALOPLACA ON SEASHORE ROCKS IN EASTERN NORTH-AMERICA

The species of the genus Caloplaca occurring on seashore rocks in east ern North America have been studied with regard to taxonomy, geographi cal distribution, and ecology. Five species were found to inhabit the coastal rocks. The species also occur in Europe, and three of them in Asia. Three of the species, C. microthallina (Wedd.) Zahlbr., C. scopu laris (Nyl.) Lettau, and C. verruculifera (Vainio) Zahlbr, occur exclu sively on seashore rocks, while C. lithophila H. Magn. and C. fraudans (Th. Fr.) H. Olivier occur also in inland localities. One-way analysi s of variance of both morphological and anatomical characters was carr ied out on the American and the European populations of the species, e xcept C. fraudans. No significant differences were found in C. lithoph ila, but in the other three species significant differences were recor ded in two or three characters. However, the differences were mostly v ery small, the overlaps large, and no discontinuities could be detecte d. Therefore no infraspecific taxa were recognized.