That's a stunning flower photo, and maybe others can tell from that and the leaf close-up. Did you take a photo of the whole plant? It might help to know how tall it was, and are the flowers all along the stem or just at the top. And what is the branching like? I agree that it's probably Cruciferae, but you're withholding a lot of information here.
The plant is about 3 feet tall, with the flowers are at the top. The leaves are much lower down at 1 feet above ground. Between the few leaves and the flowers at top, there is close to nothing, so I didn't bother to shoot the plain yhim stalk ! There are few branches, which rise up along side the main stem instead of branching out horizontally.
It looks like Arugula, Eruca sativa, but my photos of those flowers at UBCBG were from May (2018). May 2018 in the garden
@David Tang Good morning!! It seemed to me also like Eruca versicaria but I don't know if it is endemic in your area. Is this so?
I think they are the same plant. The Missouri Botanical Garden page on Eruca versicaria subsp. sativa, at Eruca versicaria subsp. sativa - Plant Finder, says that "Some authors include this subspecies in with the species and others elevate it to its own species, Eruca sativa."
