Higher taxonomic level relationships among diplolepidous pleurocarpous mosses — a cladistic overview

Abstract

The relationships between ·66 representative pleurocarpous mosses were studied using cladistic analyses. Ten different analyses were perfoqned with different outgroups or single taxa deleted to check the stability of the analyses (all resulted in too manYl!ees for other tests· of stability to be applicable). Another three analyses were performed with different sets of characters excluded to see if some kinds of characters were more important than the others for the results of the analyses. The study suggests that the Fleischer-Brotherus system has support for large parts of the classification, although the order Isobryales (Leucodontales), in the sense of Brotherus, is a grade taxon. More recent ideas about the classification of the Isobryales, which are partly based on the differences between perfect and reduced peristomes, are not supported. Jmportant and relatively stable clades are formed by (1) the species of the Amblystegiaceae (s.l.) plu~Thaidium and some members of the Hypnaceae, (2) the members of the Plagiotheciaceae (in a relatively wide sense) and (3) the Hookeriales-Sematophyllaceae-Garovagliodeae.Two of the analyses indicate that the last clade may be related t?·the Ptychomniaceae. The families· Brachytheciaceae, Hypnaceae and Thuidiaceae, in their usual sense, appear to be polyphyletic. Characters of the sporophyte and perichaetia were in general more important for the results of the analyses than characters of the vegetative gametophyte, due to their more consistent patterns of variation among the taxa. However, in some cases, such as the definition of the Plagiotheciaceae clade, vegetative gametophytic features proved to be more important than other characters.

Phylogenetic analyses reveal high levels of polyphyly among pleurocarpous lineages as well as novel clades

“…A detailed taxonomical and nomenclatural treatment of Limbella (consisting of the Hawaiian endemic L. tricostata and the closely similar L. fryei from Oregon) was provided by Ochyra (1987), who placed the genus in the Thamnobryaceae (5 Neckeraceae in our concept). There is, however, a third species, currently called Limbella bartlettii, which differs clearly from the two above mentioned ones and was treated as Vittia bartlettii, within the Amblystegiaceae (Hedenäs 2003), the family where it was also placed by, e.g., Buck (1998: 211) and Goffinet and Buck (2004). The correct use of the generic name Limbella needs further clarification but we will not address the associated nomenclatural problems in the present paper, since it has no bearing on our study.…”

“…This is especially evident in species-rich and/or single marker analyses where phylogenies of homocostate pleurocarps notoriously turn out as bushes instead of trees. However, the problem of identifying natural groups is not unique to molecular systematics as bryologists throughout the last century consistently faced this challenge while recognizing lineages solely based on the interpretation of morphological traits (e.g., Buck & Vitt 1986;Hedenäs 1995). The classification of pleurocarpous mosses even at the family level is in fact difficult, due to convergent evolution and homoplasy of morphological characters (Hedenäs 2007;Huttunen et al 2004;Quandt et al 2009).…”

Explaining the ‘anomalous’ distribution of Echinodium (Bryopsida: Echinodiaceae): Independent evolution in Macaronesia and Australasia

“…ex E.B. Bertram (Neckeraceae) in the cladistic analyses of morphological characters by Hedena¨s (1995), but relationships of these two species to other isobryalean taxa remained ambiguous.…”

Heterocladium dimorphum (Heterocladiaceae, Bryophyta) – an old element of the Hungarian bryophyte flora rediscovered

“…Brotherus (1924) divided the Th uidiaceae into four subfamilies and put the genus Heteropterum into the sub-family Heterocladioideae. Th is division was followed by Hedenäs (1995). Later, Buck and Crum (1990) revising the subfamily Heterocladioideae noted that the gametophytes of the species of Heterocladium show a remarkable resemblance to the genera Pterigynandrum Hedw., Habrodon Schimp., Iwatsukiella Buck et Crum, and Myurella Schimp.…”