Aaron's rod (ârŭnz r&obreve_;d). [See Exodus vii. 9 and Numbers xvii. 8] 1. (Arch.) A rod with one serpent twined around it, thus differing from the caduceus of Mercury, which has two.[1913 Webster]
2. (Bot.) A plant with a tall flowering stem; esp. the great mullein, or hag-taper, and the golden-rod.[1913 Webster]