An anther is a part of the male reproductive organ called stamen. It is a bilobed structure with each lobe containing two pollen sacs or microsporangia. Therefore, in total there are four pollen sacs in which pollen grains are produced. The two lobes of the anther are joined together by a connective that contains vascular tissue from the filament which provides them with nourishment.
A transverse section through an anther reveals that its wall is composed of four layers:
1. Epidermis
2. Endothecium
3. Middle layers
4. Tapetum