Lupine

A member of the Fabaceae family (aka legumes).  Tall, purple spike flowers, leaves are palmate shaped, blooms early summer, each flower produces a "bean" type pod with a few seeds.  As part of the legume family these plants are able to fix nitrogen in the soil and are an important part of the natural succession. 
If left alone, these will re-seed and spread year after year just like these in my neighbor's yard.