1. (n.) Popularly, any plant or plants growing in the sea.

2. (n.) Any marine plant of the class Algae, as kelp, dulse, Fucus, Ulva, etc.

algae autophyte bean bracken brown algae climber conferva confervoid creeper diatom fern fruits and vegetables fucus fungus grapevine green algae gulfweed herb heterophyte ivy kelp legume lentil liana lichen liverwort mold moss mushroom parasite parasitic plant pea perthophyte phytoplankton planktonic algae plant families puffball pulse red algae rockweed rust saprophyte sargasso sargassum sea lentil sea moss sea wrack smut succulent toadstool vetch vine wort wrack