Orychophragmus violaceus

I often see this flower in the street and vacant lot. wrote on March 14 2009
Their color is so beautiful, especially when they bloom in clusters.
It has Japanese common name "flower radish".
I heard that the leaf is edible.
But I'll never eat them, because I have only several stocks in my small container.
I'll enjoy seeing them, and I'll draw if I have time.