RPS4 and NAD5 sequences indicate the polyphyly of ditrichaceae and parallelisms in the evolution of haplolepidous mosses

The molecular phylogenetic analysis of 66 representatives of haplolepidous mosses indicated that Ditrichaceae family is polyphyletic. According to the data obtained, the structure of peristome, as well as gametophyte features, which has been traditionally used to allocate this family, arose independently in different groups of haplolepideous mosses. At least six genera ( Distichium, Saelania, Eccremidium, Garckea, Rhamphidium , and Wilsoniella ) should be excluded from the Ditrichaceae family, including Saelania and Distichium, should be attributed to another orders. The loss of peristome and the formation of cleistocarpous capsules also occur independently in at least two lineages of Ditrichaceae s. str., as well as in representatives of several lineages of Pottiaceae, a family derived from this group. Ditrichum , a type genus of Ditrichaceae, is also polyphyletic; the species of this genus belong to two clades. It was concluded that parallel lines of morphological variations in this group of mosses occur and its phylogeny needs to be resolved based on molecular data.