Until recently, fossils of plants have been of spores or pollen, mostly due to the toughness of the spore and their walls. Spore deposits dating from the Silurian and Devonian demonstrate to us that they can very well resist decay and remain numerous.
The outer wall of spores (exine) has a very important component, a waxy compound known as sporopollenin, which is also found in the wall of pollen in angiosperms. This compound is simply one innovation that allows for plants to thrive on land and to disperse to various habitats. Sporopollenin allows for great resistance against environmental stresses, allowing spores to disperse in the air without drying out and to stay dormant until conditions are favourable for germination. The chemical composition of sporopollenin is not yet known.
Along with sporopollenin, the exine is also composed of polysaccharide deposits which sporopollenin are impregnated within. A callose deposit before the exine forms is obtained by each spore. The intine, the inner wall of the spore, is formed after exine formation and is composed of cellulose and other polysaccharides.
The ornamentation on the surface of the spores of some mosses is due to a layer known as perine. This layer is basically composed of left overs from the walls of the spore mother cell and the columella.
There is currently not a lot of research done to link ornamentation with potential spore dispersal mechanism as previous studies have not been to successful. However, we will be including our predictions on how these ornamentations on the spore wall help various species disperse and germinate more efficiently.
Moss Spores & sem 