Mistletoe (Viscum album) is one of the only plants that we know was sacred to the Druids. It represented both peace and divine masculinity (and therefor fertility). Hang boughs of it, or stuff it into snail shells for prosperity, love, fertility, and peace.
"The Druids considered mistletoe a holy plant that protected from evil and had great medicinal value. Mistletoe didn’t begin quite so well in Norse mythology: the arrow that killed Baldur, beloved of the gods, was carved from mistletoe. The Norse gods then judged that henceforth mistletoe would be under the command of the goddess of love, in order to negate its use for hate—that’s one explanation of why those who stand under the mistletoe are expected to kiss. The other explanation is that mistletoe was previously incorporated into Saturnalian wedding celebrations (Saturnalia was a Roman winter festival upon which Christmas was based). A Sun herb, mistletoe fights against despair, protects, and helps in hunting and conception. Unusual for a Sun herb, this magick herb is connected to dreams and to learning about immortality through dreams. It has been made into wands and is said to ward off werewolves and thieves. In the Ogham alphabet, mistletoe is a Chieftain associated with spiritual healing and development.” -Alchemy Works