Medieval manuscript of a phallus tree.

From a Facebook post by a reenactor that I know.

http://3.bp.blogspot.com/_yAdUICQZuA4/S3nZFWVWfnI/AAAAAAAABN8/QXSOu-Iw2SM/s320/nunphallustree.jpg

This is from a real 14th century manuscript, the Romance of the Rose. And yes it is exactly what it looks like, a nun picking giant penises out of a tree.

There's a couple of article type things on GotMedieval

http://www.gotmedieval.com/2010/02/just-a-fruit-tree-i-swear-innocent-whistle.html

and here http://www.gotmedieval.com/2008/10/negative-campaigning-medieval-style.html

The bit about the Nonnenturnier, which is apparently a medieval German story, in which a man quarrels with his penis so much that it decides to leave him, eventually ending up at a convent where a group of nuns hold a tournament to determine who will get to have it, is possible one of the crackiest ideas I've heard for a story.