Sporophyte characters

However, through the study of additional plant material, it became more and more clear to me, as well as other researchers, that in some cases the reliance on sporophytic characters to build phylogenetic alliances among the pleurocarps not only is suspect but actually can lead to erroneous conclusions. 

Howard Crum (Figure 1.10) and I (Buck and Crum, 1990) relied totally on gametophytic characters in defining familial boundaries of the Leskeaceae/Thuidiaceae complex even though traditionally the families were separated on sporophytic differences (sometimes even into different orders). We allowed, within a single family, sporophytic evolution in which fnlly developed hypnoid peristomes can become greatly reduced. We correlated these reduction seqnences with differences in habitat. 

Zanten (1959) suggested that Trachypodopsis is closely related to the Meteoriaceae based on some shared morphological characters, such as auriculate leaves, unipapiUose leaf cells, sporophytic characters and occasionally pendent habit. Within the family. Buck (1994) placed it close to Toloxis. In our analyses its position was affected by inclusion of morphological data (see Huttunen et al., 2004), although support was in aU analyses very tow or even lacking. 

Problems with the Interpretation of Some Sporophyte Characters.237... 

Molecular and morphological evidence combined (Huttunen et al., 2004) support a close relationship of most of the above taxa, including the Meteoriaceae, which were considered problematic in Hedenas (1995) study because species with unspecialized and specialized sporophytes appeared to have different ancestors, even if the characters of their vegetative gametophytes suggested otherwise. 

Note States of sporophyte characters refer to the condition in species with unspecialized capsules and peristomes. In orthotropous capsules the character states are partly very different from those given and, in addition, many similarities... 

PROBLEMS WITH THE INTERPRETATION OF SOME SPOROPHYTE CHARACTERS... 

Besides frequently having orthotropous capsules, epiphytic pleurocarps possess several other sporophytic character states more often than species of other habitats. These include short setae, ovoid to cylindrical and straight capsules, round stomatal pores, lack of or a poorly developed separating annulus, rostrate lids, papillose lower exostome outer surface, reduced exostome primary... 

FIGURE 11.2 Patterns of correlations among characters of the vegetative gametophyte (GAM) and the sexual branches plus sporophyte (SPO), respectively. One correlation implies that one or several states of a specific character is or are correlated with one or several states of another character. The bars thus show the number of correlations between an average GAM or SPO character, and other GAM or SPO characters. (Adapted from Hedenas, 2002.)... 

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