Nereocystis luetkeana - Bull Kelp
is an annual kelp, growing anew each year from spores.
Interestingly kelps, which are also known as laminariales,
make up the order Phaecophyceae, or brown algae.
This one washed onto the beach.
In the foreground we see the holdfast with its many fingers with which it attaches to rocky substrates.
Going up from the holdfast is the long stipe
with the buoyant, gas-filled bulb called a pneumatocyst, at the top.
Blades extend from the top of the pneumatocyst and are the plant’s photosynthesizing structures. These blades are what we see floating on top of the water.