Leaf shape does not look right for Waterhemp.

On Palmer, when you bend back the leaf petiole over the leaf, the leaf petiole is longer than the leaf blade.  The leaf petioles on your sample are not that long.

When I look at the first pic, looking at the long branch (stem) that goes right, it looks like there are small fuzzy hairs across that branch (stem).  Both Waterhemp and Palmer are smooth - no hairs.  Both redroot and smooth pigweed have small fuzzy hairs on the stem.

According to the Pigweed ID guide I have from K-State, it says redroot and smooth pigweed are hard to differentiate until they are mature. 

Redroot pigweed - Branches    of    the    flowering    structure    are    very    compact,    usually    less than 2 inches long, and thicker than a pencil.

Smooth pigweed - Branches    of    the    flowering    structure    are    compact,    usually    more    than    1½    inches    long,    and    thinner    than    a    pencil.    Branches    are    usually longer than those of redroot pigweed.

My guess is similar to DKO - I think you have Redroot pigweed.

Kansas State pigweed ID