The story
From fire + weed. The fire-part may be of same origin as eld-part in dialectal Norwegian Nynorsk eldmerke (“fireweed”).
Etymology from Wiktionary, CC BY-SA 4.0.
fireweed
Today it means: A perennial herbaceous plant (Epilobium angustifolium or Chamaenerion angustifolium) in the willowherb family Onagraceae. Full definition →