In Southern California right now it's the season of mustard, a horrible invasive species that overruns our hillsides seemingly earlier every year. This year there were only a few weeks of early spring greenery before everything started turning yellow.
Still, like nearly any plant, it can be made to look pretty.

We have had frequent invasions of mustardweed in New Mexico, too. It spreads throughout one's yard (and the Open Spaces) like a plague. But this year, even the weeds are mostly failing to come up! It's that dry.
At least it's not star thistle or foxtail!
I grew up in Southern California and spent plenty of time pulling foxtails out of my clothing, dog's fur, cat's fur....
invasives are introduced by us humans precisely because they are perceived to have some value, beauty being one of them. by the time we figure out that they're invasive pests, the proverbial cat is out of the bag (with apologies to hilbert and charlie).
Mustard is a natural biofumigant that kills nematodes in particular and suppresses the growth of other plants that are even harder to control.
Wasn’t mustard introduced into California by the Spanish? Or is that recollection in error?
Russians, I believe.
Interestingly enough, web searching gives both answers. Perhaps it is a litmus?-)
The other plants need to ketchup with the mustard…