The photo below came from Trent Amonett of Pullman, Washington. He writes:
I took the attached photo this last weekend. We’re in the dearth here in Pullman, and my bees are visiting food sources in my yard, which they normally don’t do. The thistle is a perennial that came with the house. I came close to pulling it the first spring after we moved in until it turned a pretty silvery blue and I realized it wasn’t a weed. Anyway, I like the photo a lot, and everyone I’ve shown it to so far has been more interested in the thistles when to me it’s about the bees.
Update: Thanks to all the folks who correctly identified this plant as Sea Holly, Eryngium planum.