I've seen this along roadsides in various places.
Southern California weed
I don't think it's a Baccharis - it appears to be herbaceous and not woody. It looks like Chenopodium berlandieri or something related. https://www.google.com/search?hl=en&site=imghp&tbm=isch&source=hp&biw=1649&bih=909&q=Chenopodium+berlandieri
Thanks Tom, it definitely looks to be in the Chenopodium family. I'm looking for species that match the colors. What do you think about C. murale?
one last bump; any one know which species of chenopodium? c. murale is my best guess based on pictures.