Pollen is a powdery substance that consists of pollen grains, which contain the male reproductive cells (of angiosperms). Pollen is produced by the anthers of seed plants and is the fertilizing element of flowering plants. In gymnosperms, pollen is produced by male cones. Each pollen grain divides into two nuclei and a tube cell. The tube cell grows into a pollen tube to conduct the nuclei into the ovule.