A leaf from a plant growing outside April's bedroom in the Border House. It's actually organic plastic: as April says, 'It grows, and it converts carbon dioxide into oxygen. Convenient! - but disturbing.' Although the leaf is not used in any actual puzzles, if April plants the leaf in the City Green in Marcuria, it will open The Longest Journey's Book of Secrets.
Fiona also mentions to April that she's going to watch a documentary about the new artificial rainforests of Mexico (possibly on the Yucatan peninsula), that convert CO2 even more efficiently than real foliage; this is the documentary that briefly transforms the Border House's living room.
Obtained from the Border House's upstairs corridor.