Aaron's rod

Short definition from Wiktionary

Noun

1. 1
   Any of various plants with a tall flowering stem, especially: Verbascum thapsus, the great mullein, common mullein, or hag-taper.
2. 2
   Any of various plants with a tall flowering stem, especially: Goldenrod, the Solidago genus of North American plants with yellow flowers.
3. 3
   Any of various plants with a tall flowering stem, especially: Hylotelephium telephium (syn. Sedum telephium; orpine, livelong, or live-forever).
4. 4
   A rod-shaped molding decorated with an entwined snake, and sometimes leaves, vines, and/or scrolls.
5. 5
   A rod with one serpent twined around it, as used by Aaron (differing from the caduceus of Mercury, which has two serpents).