Sexual Reproduction In Flowering Plants

A typical anther wall is four-layered, as detailed in NCERT Class 12, Chapter 2 (Sexual Reproduction in Flowering Plants), comprising the epidermis, endothecium, middle layers and the innermost tapetum. The tapetum is the layer in direct contact with the microspore mother cells and the developing pollen, and its cells are dense with cytoplasm, often containing more than one nucleus. It supplies nutrients and contributes materials such as the sporopollenin-rich pollenkitt needed for pollen wall formation. The endothecium is incorrect because it lies just beneath the epidermis and aids dehiscence of the anther rather than nutrition. The middle layers are short-lived and lie between endothecium and tapetum, playing no major nutritive role. The epidermis is the outermost protective layer and does not nourish microspores. A consistency check confirms the answer: nourishment of pollen must come from the layer closest to them, which is the innermost tapetum, exactly matching the requirement of the question.