The mustard family, officially called brassicaceae, is one of the star players in the wild food game, because every species in the mustard family is edible. That means that as long as you can positively identify a wild plant as a brassica (a nickname for members of the mustard family), you know you can eat it. And for most families this can still be rather difficult to do, but brassicas have a unique feature that most families don’t have: a simple set of rules to identify any member of the family.
And here it is: all brassicas have flowers with four pedals, and every flower has four tall stamens, two short stamens, and one pistil.
Now, I wouldn’t bother giving this little botanical anatomy lesson if it weren’t so incredibly useful for identifying brassicas.
These flowers may come in different colors, sizes, etc, but those rules always apply. And if the plant is a brassica, it’s a food plant.