Sea Cauliflower     Leathesia difformis

This yellowish brown seaweed is a member of the marine algae group called brown seaweeds or Phylum Phaeophyta.  The big seaweeds called Kelp belong to this same group.  The Sea Cauliflower is a sack-like, multi-lobed plant that is composed of filaments and will disintegrate when pressed between the fingers.  It often occurs alone as shown in the photograph or can be found in large clumps.  

When young it is solid and might be confused with another brown seaweed called the Brown Bag (Colpomenia bullosa).  However it hollows as it grows and retains the rough, brain-like appearance.  Starting growth in late spring and finally disappearing in early fall, this two inch, average-sized specimen might attain a size of six inches in diameter .

It is common on rocks or some seaweeds and sea grasses in the mid to low intertidal zone.  The species can be found in the eastern Pacific Ocean from the Bering Sea to Baja California.  It is also present in Europe and Chile.