Very similar to 'Field Mustard'. Does not have hairy stems and leaves like Field Mustard [Brassica rapa].
This just came up in a container. Instead of pulling it, I let it grow. It has a very pretty yellow bloom. Shown at the end of March. (San Antonio, Tx.)
Grown as a crop In Alberta, Canada. Harvested and made into cooking oil etc.
Here a Painted Lady, (Vanessa cardui) employs the Canola blooms for nectar...
As this Canola was just coming up near the bird feeders...
Here is a Cabbage White butterfly scoping this plant for oviposition on March 20, 2008. I still need to check for any larvae about now, (April 6).
Straight on of the Canola bloom cluster..