Sporopollenin is one of the most chemically inert biological polymers. It is a major component of the tough outer (exine) walls of
plant spores and
pollen grains. It is chemically very stable and is usually well preserved in
soils and
sediments. The exine layer is often intricately sculptured in species-specific patterns (see image at right), allowing material recovered from (for example) lake sediments to provide useful information to
palynologists about plant and fungal populations in the past. Sporopollenin has found uses in the field of
paleoclimatology as well. Sporopollenin is also found in the cell walls of several taxa of
green alga, including
Phycopeltis (an
ulvophycean) and
Chlorella.
