The wonderfully-named glen "My Lord's Throat", east of Alford, Aberdeenshire, has a surprisingly western bryophyte flora for a location on the east of Scotland.
Granite boulders are strewn over the steep slopes in this birch woodland, providing a niche for species favouring acid rocks. The photo shows a rich-green mound of Polytrichum accompanied by paler cushions of Bryum.
Bryophyte "organs and tissues" may resemble those of vascular plants, but they must have evolved separately and are not homologous morphological structures. To see why this is so, you have to remember that the leafy moss plant, the gametophyte, comprises haploid cells. Cells of this ploidy in flowering plants are found in the pollen grains and the ovules, while the leafy shoots are part of the diploid sporophyte plant body. The sporophyte on mosses comprises the semi-parasitic seta and moss capsule.
And so although we use terms such as shoot and leaf to describe parts of mosses that play similar roles to the same-named parts in vascular plants, they arise in a different generation in the life cycle. If a pollen grain or ovule developed photosynthetic shoots and leaves, we'd have something more akin to the moss gametophyte.
The overall similarity in plant structure between moss gametophytes and vascular plant sporophytes must be the result of convergent evolution.
To reflect these different origins, technical terms for the shoot-like and leaf-like parts of mosses have been defined, although these are rarely used by bryologists. However, this distinct nature of moss parts is worth bearing in mind and may go some way to explaining the ways in which moss "shoots" and "leaves" can demonstrate innovations in form and structure that are not found in vascular plants.
Cloch Burn drops over the cliffs at the Corrie of Balglass near Fintry, Stirlingshire, creating a variety of niches inhabited by a range of mosses and liverworts.