Quiz "plant: algae"
any of a group of unicellular biflagellate aquatic organisms forming a constituent of plankton: now usually classified as a phylum of protoctists (Dinoflagellata)
any of several seaweeds of the genera Fucus and Ascophyllum, esp F. vesiculosus, that grow in the intertidal regions of rocky shores and have branched brown fronds with air bladders
any of several seaweeds, esp Rhodymenia palmata, that occur on rocks and have large red edible fronds
any floating brown seaweed of the genus Sargassum, such as gulfweed, of warm seas, having ribbon-like fronds containing air sacs