ИСТИНА

olecular phylogenetic studies of mosses revealed two terminal clades, the subclasses Bryidae and Dicranidae, largest in number of species, and the grade leading to them from primarily eperistomate and nematodontous groups through Buxbaumiidae, Diphysciidae and Funariidae. Buxbaumiidae and Diphysciidae have highly specialised peristomes, not splitting into definite number of separated elements. The three subclasses, Funariidae, Bryidae and Dicranidae are characterized by three main peristome types: diplolepideous opposite, haplolepideous, and diplolepideous alternate respectively, and this correlation is a fundamental fact of the backbone moss system. The recent anatomical studies of the peristome development, however, challenge some its aspects: (1) origin of the Diphyscium peristome type from the Buxbaumia-type; instead Buxbaumia is likely a derivative from Diphyscium-like ancestor; (2) the occurrence of diplolepideous peristomes in some groups of Dicranidae (which are commonly called just "haplolepideous"); (3) The opposite position of elements of endostome and exostome may repeatedly appear as a kind of peristome reduction, thus Funariidae may be assumed not as one of three basic peristome types, but a side lineage, representing several variants of strongly modified peristome types.