Dendromecon rigida?

Grrrr Houzz ate my reply.

I don't think that's quite it. I will add better images, and pace them so as not to offend Houzz.

Better flower image:

Overall plant. (See where it is free and heavily flowering on the Other Side?)

Looking at all the new growth, I wouldn't be surprised if this is not evergreen in most places.

Stems have pronounced ridges.

What about Jasminum nudiflorum, winter flowering jasmine?

Deciduous in UK, but in SF??

Thanks! After looking at them both, it really does look more like J. mesnyi...except it doesn't smell!

What luck. I get the one mutant that doesn't smell. :)

J. nudiflorum doesn't smell either.

C'est la vie. :-)

I don’t think I’ve ever encountered a P. mesnyi that had a fragrance.

Definitely J. mesnyi (primrose jasmine). It's drought-resistant and good for an "informal screen." I don't remember any fragrance either.

A few websites list it as fragrant. They're probably just referencing each other. I'll take this one from OSU: "listed both as fragrant and unscented".

https://landscapeplants.oregonstate.edu/plants/jasminum-mesnyi

I really do like most of the stinky jasmines.

For future reference, nudiflorum has smaller, single flowers with less rounded petals.