|Sea braid, aka sea comb, Plocamium pacificum. About 4 cm. The whole plant may be up to 25 cm. long.|
|Zooming in. The tiny branchlets each have three tinier branchlets off to one side.|
And looking at those tiniest branches under the microscope, at 40x, I can see that they also wear mini-branchlets.
This seaweed grows on rocks in the lower intertidal zone, which is why, when I find it close to the shore, it is always a fragment.