Washed up on Balboa Island, Newport Bay. I'm not familiar with this one, and these stalked air bladders. Invasive.
Small (20cm long) piece of immature S. muticum found in beach wrack, tangled with Macrocystis, Cystoseira, and eelgrass. Prevalence uncertain – was out at night so it was difficult to see if it was anywhere else on beach.
Identifying features: single thallus, spherical air bladders. No reproductive conceptacles visible.
Immature S. horneri among beach wrack, tangled with Macrocystis and eelgrass.
Prevalence uncertain – this is an observation from a few months ago and I can't remember how much there was on the beach.
Identifying features: football-shaped air bladders, some fern like leaves, no conceptacles.