help identifying this plant

Seattle area, I can almost watch it grow right now, it's starting to flower, and the bees like it.

Looks like Melilotus albus or white sweet clover. It's a nitrogen fixer, attracts beneficial insects and is used for bee and other animal fodder.

Thanks. I think you've nailed it. It came up between my blueberry bushes, but I guess I'll keep it!