Crossidium laxefilamentosum Frey & Kürschner (Bryopsida: Pottiaceae), new to Europe and to North Africa.

Crossidium laxefilamentosum Frey & Kürschner is shown to be a distinct taxon that is easily distinguished from the related C. crassinerve. Discovery of two plants of C. laxefilamentosum with sporophytes has permitted the description of the capsule and spore characters for the first time. This species is recorded as new to Europe and to North Africa. The known range of this desert species is now expanded from South-West Asia to North Africa, to the steep loess cliffs along the River Danube, and to the dry S. E. coast of the Iberian Peninsula. Among these regions five localities are reported from northern Serbia, three from central Hungary, S. of the 47° line of latitude, one from Romania, 20 from Spain and six localities have been found in Tunisia. The distribution of C. laxefilamentosum suggests that it had a circum-Tethyan origin. [ABSTRACT FROM AUTHOR]