Mystery Weeds - - Need help identifying!!

Hello, I am an agronomist intern for the summer and have a scavenger hunt to

complete before I am finished in July. I have most of the weeds, insects and

fungal/bacterial pests identified for the area, however, I have stumbled across a

few which I have no idea as to what they are, despite my research & knowledge. I

will post pictures below, and if anyone has any answers, I would gratefully

appreciate it!

Thank you 

#1. Appears to be similar to purslane, but the leaves are not as succulent with various other differences.

 #2. Wild, wild flower! Have never seen this before!

 #3. Herbicide damage? Maybe possibly a leaf scorch or purple leaf blister? Found in a winter wheat field, with no damage to the crop itself.

 #4. Resembles a thistle of sorts, but with the smooth broad leaves, I am puzzled? Yes, the flowers are light purple, sorry about the poor photo quality.

 #5. NOT knotweed!!!

 And finally, #6. I see this frequently, from corn to oat fields, but cannot find any leads what so ever!

Thank you so much for taking the time to view my post. If you have any ideas,

or insight, please feel free to share!