Bull Kelp
A favorite beach find for many youngsters is a long, whip-like, dark brown alga called “bull kelp” (Nereocystis luetkeana). The living plant is attached to offshore submerged rocks by a special part called a “holdfast” and is buoyed in the water by a hollow float from which thin blades extend. The holdfast is on the narrow end of the whip. This is an annual plant and attains its large size in only one growing season.
Source: Flotsam, Jetsam and Wrack.
Sea Palm
Another often-seen algae look like a small, olive-green palm tree. Naturally, its common name is “sea palm” (Postelsia palmaeformis). This pliable but hardy plant lives attached to rocks in tide pools only where the waves pound the hardest. When you see this plant alive on tide pool rocks, be wary of big waves! It, too, is an annual.