An example of a marine angiosperm is the seagrass. Seagrasses are marine flowering plants that grow in shallow waters and form extensive underwater meadows. They play a crucial role in marine ecosystems, providing food and shelter for various organisms and contributing to nutrient cycling and sediment stabilization. Examples of seagrass species include Zostera marina (eelgrass), Halophila ovalis (shoal grass), and Thalassia testudinum (turtle grass).