Meanings

Brazilian elodea (Egeria densa)

waterweed (any aquatic plant of genus Elodea, esp. common waterweed, Elodea canadensis)

Eurasian water milfoil (Myriophyllum spicatum)

whorl-leaf water milfoil (Myriophyllum verticillatum)

Eurasian water milfoil (Myriophyllum spicatum)

Notonecta triguttata (species of backswimmer)

Ochromonas vischeri (species of golden alga)

hydrilla (species of aquatic plant, Hydrilla verticillata)

cryptophyte

glaucophyte

chlorophyte

dinoflagellate of genus Ceratium

seaweed

seaweed bed

Sargassum fulvellum (species of edible brown alga)

stoneworts

stonewort (esp. Braun's stonewort, Chara braunii)

charophyte

cyanophyte

Oscillatoria (cyanobacteria)