Tapetum (botany)

A tapetum is in botany, a single-or multi-layered tissue plasma- rich cells on the inner wall of the spore cases of ferns and pollen sacks of seed plants, which serves for the nutrition of the spores or pollen grains.

The diet of the spores can be carried on secretion ( Sekretionstapetum ), as is the case with Bärlappgewächsen. On the other hand, the cell walls of the tapetum can also dissolve and merge, so that the resulting protoplast may distribute amoeboid between the pollen grains ( Periplasmodialtapetum ). This can be found for example in horsetails.