Can anyone identify this plant? It is growing in one of the raised beds the previous owner had built. They had some flowers, herbs and vegetables growing in this particular bed. As you can see from the pics it grows in clumps from a long root, is invasive. The stems are round and hollow, like a chive but much thicker/stronger walls. It is now 'blooming' with a single flower stalk as seen in the one picture. Currently it is about 18 inches tall.

Thanks!

Charles

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