Seagrasses have two methods of reproduction: they can reproduce asexually or sexually. When they reproduce asexually, or clonally, rhizomes elongate beneath the sediment and new, genetically identical shoots are produced. This method of reproduction is important in the expansion of meadows, but it is relatively small in scale, since all shoots must be connected. Seagrasses can also reproduce sexually by means of flowers. Some species of seagrasses have distinct male and female flowers, while others have both male and female parts within the same flower. When the male pollen fertilizes the female ovary of the flower, new genetically unique seagrass shoots are produced. In addition, flowers or their fruits can break off and travel long distances through the water. This is essential in the creation of new meadows.