Sporophyte structure

The Brachytheciaceae is a diverse group of mosses, and most of its representatives are mesic plants of forest floor, tree bases, fallen logs, rocks in forest, etc. The Brachytheciaceae have colonized two extreme habitats tree trunks, which led to many morphological parallelisms in sporophyte structure. 

It is important to note that the main diagnostic characters of pleurocarps (gametangia position, sporophyte structure, presence of leaf-like structures around branch primordia and dormant buds, etc.) are usually not available in fossil collections. Thus, we have no other way than to be satisfied with the less taxonomically important characters, such as pattern of laminal cell areolation, density of foliage, presence/absence of costa and branching pattern. 

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