Seaweeds and seagrasses 

Do you know your seaweed words?
Algae a name for the plants that include the seaweeds.
Pigment the major groups of seaweeds have different pigments that absorb or use different types of light.

Holdfast the end of some seaweeds have a base that is glued to rocks.
Bladder a round ball-shaped part on some seaweeds.
Seagrass meadow usually an area of sandy shallow sea covered by seagrass.