Herbarium

Herbarium can be crafted with a 'Book and Quill' some slime balls and string. You could then right click the Herbarium on any plant of your choice to save a piece of it or the whole plant to your little book. If you right click a Poppy the flower is broken and is saved to the Herbarium. But if you right click some Oak leaves when you open the Herbarium to the page the leaves are at you only see a few leaves, even though the block itself looks like it has a few dozen. There would also be an achievement for completing the whole herbarium i.e. collecting all the plants that currently live in Minecraft. Also the name of the achievement could be a reference to Hemulens from The Moomins.