I have had no luck trying to id this plant that sprung up in the garden over the summer. The flower has five yellow petals, all sort of connected so it looks like one big petal. The anthers are bluish-purple. Look at those green bulbs! What the heck is this plant? The leaves are long and ace-shaped, with slightly toothed edges. The stem is square and hardy, grew to four feet tall in just a couple of months! I live in the Pacific Northwest and we've had a pretty warm last couple of months. Thanks for any clues!

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