Microsporangia are surrounded by a thin layer called the tapetum.
Multinucleated and polyploidy tapetal cells make up the tissue. Pollen grains
develop as a result of them. Ubisch bodies are found in these cells and contribute
to the ornamentation of the microspores and pollen grains. Sporopollenin is a
substance produced by the Ubisch bodies of the tapetal cells. This substance is
present on the exine layer of pollen grains. A spiny appearance is attributed to the
exine of pollen grains due to the presence of this compound•