Glad we have you Toni to help us know what plant is what plant. I will have to check out that knapweed plant. Sounds interesting.
She calls them giant yellow batchelor buttons. I do not know if that is the common name in Oregon or what. However, as you noted and another friend they are 'yellow centaurea' and batchelor buttons are 'centaurea cyanus' [blue]. Both are centaurea, which is batchelor buttons. I will try and specify it when I mention it, or post pictures. The buds are open far enough to see the pinecone looking thing inside. It has been drippy and raining all day, so I did not get a new pic of the bud. Perhaps the weather will cooperate tomorrow.
I was finally able to get to town today, and those purple flowers do have a square stem, so I guess they are the bee balm. They have gone to seed already, and the store manager okay'd it for me to get some seed heads. Yay. Now I have to find out when and where to plant them. I guess they won't be up until spring, but that is okay.