Canyon Gooseberry. I have not seen these growing wild in SB, though they are supposed to be found in the eastern part of the county. However they seem to be a favorite for revegetation efforts, and so they are quite easy to find. There are lots down near the new footbridge between Arroyo Burro Beach and the Wilcox (Douglas Preserve), a few at Steven’s Park near the start of Jesusita Trail, and even one in the Turnpike bioswale.
It seems to have the largest and showiest bloom of all the gooseberries (not that that is saying much) and that may be why it is chosen.
I have seen it blooming between December and March.