Barbarea Vulgaris

I posted yesterday some of the details of my DIY Macro Camera lens.  Here now is an example of what it does.

These yellow flowers are Barbarea Vulgaris (I think... I am not a trained botanist.) also known as Yellow Rockets or Yellow Rocketcress.  They are named after St. Barbara - patron saint of artillerymen and miners - as the flower was sometimes used to treat wounds caused by explosions.  Apparently the leaves are edible.