Even experienced gardeners make mistakes. Good Old Bindweed. I could have sworn that it was the morning glories (heavenly blue, of course) that I planted from seed this spring. It grew up right at the base of the trellis, I thought for sure it must be. But no, it was bindweed. I thought (foolishly) that for sure this would be my best year ever for morning glories. Not quite. They look similar- the key, of course, is the flowers.
Only thing to do is rip it out and hope it didn’t reseed for next year. Yikes!