It’s Helminthotheca echioides, commonly known as Bristly Oxtongue. Possibly the plant got its English name from the leaves, which are rough, pimply, long and pointed. The bovine tongue is also rough and pimply (covered with papillae, small projections), and is long and pointed. However, the bovine tongue doesn’t have spikes.
In the Welsh language, the plant is called lion’s tongue. In German, it’s Wurmsalat — worm salad, see below.
Helminthotheca is believed to come originally from around the Mediterranean, but has been naturalized in the wild for longer than probably any person alive in California today.
It’s listed as a weed by Calflora, which tells you that nobody so far has adopted it for their garden. It’s also listed as “characteristic of disturbed places,” which is totally true of Cesar Chavez Park.
Wikipedia adds that this plant “was traditionally used as an antihelminthic treatment,” meaning to expel worms and similar parasites from the mammalian body without killing the mammal. However, modern listings of anti-worm treatments don’t list this plant as effective.
Below also is a pic of a bovine with its tongue extended, performing the very useful chore of cleaning a nostril. Do you think that this animal would like to eat this plant?