Pinnate Tansy Mustard looks very much like the Pineapple Weed previously mentioned, except that the leaves are more feathered with symmetrical branching look, unlike the PW which has more carrot-leaf look to it.
Yes it is edible, much like any mustard greens (no I haven't tried it, being the side of the street plant). Another cousin of it looks similar, Flixweed, which is an introduced species from Europe. Tansy Mustard is native to North America.
The seeds were used by the native North Americans as food, and has been traded prior to the introduction of modern grains, like wheat. It is, however, toxic to livestock, which is why this plant is not very popular with farmers.
