The parts of the ocean shallow enough for them to get sunlight and rocky enough for them to hold on often are:
https://en.wikipedia.org/wiki/Macroalgae
(Not technically plants, but basically sea plants.)
The parts of the ocean shallow enough for them to get sunlight and rocky enough for them to hold on often are:
https://en.wikipedia.org/wiki/Macroalgae
(Not technically plants, but basically sea plants.)