New paper on invasive seagrass flowers: male plants first to colonize new habitats?

Seagrasses are marine flowering plants that can reproduce both sexually (through flowering and subsequent seed formation) and asexually (through clonal growth). Sexual reproduction increases genetic diversity, resilience and dispersal success of seagrasses.

The invasive seagrass Halophila stipulacea originating from the Red Sea and Western Indo-Pacific, has been successfully invading the Mediterranean Sea since 1894 and the Caribbean Sea since 2002.

In this new paper, we found that so far, only male flowers have been described of the successful invasive seagrass species H. stipulacea in the Caribbean Sea. Female flowers and fruits have not been reported. This means that fragmentation and fast clonal growth may be the only factors explaining its current success. This needs to be taken into account in further studies studying H. stipulacea expansion.

In-depth monitoring of reproductive structures in invaded seagrass meadows, both in the Mediterranean and the Caribbean Sea is important to assess further invasion potential. Given past misunderstandings regarding the identification of H. stipulacea reproductive structures, we have developed a field guide with a dichotomous key, to take into the field and identify the various structures by eye. https://doi.org/10.1515/bot-2020-0046