Mistletoe: Kiss.
Spruce tree wreath: Firm handshake with eye contact.
Blue spruce tree wreath: Firm handshake with eye contact, but eyes betray glint of unspeakable melancholy.
Holly berry: Awkwardly go in for hug of coworker and only when it is too late realize they were actually just trying to get to one of the remaining pieces of fudge that HR left in the break room on the table behind you.
Juniper bush: Set bush on fire and hide, then yell to passerby that you are an Angel of God sent to condemn heathens for taking Christ out of Christmas; bonus points if you remove your sandals and fire does not consume bush.
Amaryllis flower: Remark to your one Jewish friend Greg about how it was pretty crazy that Thanksgiving and Hanukkah were on the same day this year, then slowly and silently back away as he explains to you that Hanukkah is a multi-day event.
Bonsai: High five in style of Goose and Maverick from Top Gun (note: in some regions, only appropriate if bonsai is encountered in conjunction with playing Christmas Day shirtless beach volleyball tournament).
Sprig of parsley: Ask someone if you have something stuck in your teeth; lick their face when they lean in to look.
Fig leaf: Repeatedly say, “I think we’re going to need a bigger fig leaf” in your best Richard Dreyfus voice while raising eyebrows suggestively and looking down at your groin; most effective if done when wearing a gaudy holiday sweater and nothing else.
Poinsettia: Eggnog keg stand.