Made for the CCSF 2016 by Allekha! The description is as follows:
Mary, Mary, quite contrary, how does your garden grow? With silver bells, and cockle-shells, and quite odd plants all in a row.... The Mary-Mary plant was discovered by a strange Shee who insists it popped out of a story book. They sleep at night, but during the day, they occasionally produce cockle-shells for your creatures to eat. They live a long time, but spread slowly, so they shouldn't take over the place.