Buttercup flower. Coloured scanning electron micrograph (SEM) of the reproductive structures of a buttercup (Ranunculus sp.) flower. The anthers (male structures) surround a central group of female structures that are tipped with stigmata (brown). The anthers produce pollen grains, each containing a male reproductive cell (male gamete). Pollen is transferred between the flowers of different buttercup plants, and each stigma can receive a pollen grain and transfer the male gamete to an ovary (not seen) where the male gamete fertilises the female gamete, producing the seed for a new plant. Magnification unknown.