a fine powder produced by flowers, which is carried by the wind or by insects to other flowers of the same type, making them produce seeds.——朗文当代大辞典

The fine granular or powdery substance produced by the anthers of a flowering plant or the male cones of a gymnosperm, consisting of microscopic grains (microspores) that each contain a developing male gamete. Also (frequently with distinguishing word): this substance produced by a particular kind of plant.——牛津当代大辞典  @en