If you don't get a response here, try the Name that Plant forum.

Looks like turnera subulata. I have this plant in my yard. The bees like it. Flowers come out in the morning and close in the afternoon.

Doubt if this plant is fussy where it grows. The leaves on mine go yellowish too.

I chop back, rather harshly, the ones I want to keep. Makes them bushier instead of rather spindly. I also pull up the ones I do not want.

This plant reseeds itself in my yard quite readily, and you sound like you are in the same climate as me.