bundweed

\\ˈbənˌ(d)wēd, ˈbu̇n-\ noun

Etymology: alteration of earlier bunweed, from Middle English bunwed, perhaps from bune hollow stalk + wed, weed weed — more at bun, weed I

dialect England : any of various weedy plants (as the knapweed, ragwort, scabious, or cow parsnip)