Wild Mustard

Sinapis arvensis: Wild Mustard

Vitamins A, C, D, K, folate, potassium, calcium, iron, fiber, phosphorous, and iron. 

Remove stalks, boil to take away bitter taste, then use as you would spinach.  

References: http://www.pennilessparenting.com/2011/03/wild-mustard-foraged-food.html
http://oregonstate.edu/dept/nursery-weeds/weedspeciespage/wild_mustard/flower_5_750.jpg