Select the Plant library icon.

At the top of the library, you'll see a search bar.

Type the name of the plant you're looking for. This could be its common or Latin name. For example, if you're looking for a maple tree, you can type "maple" or "Acer." Sometimes, even just part of a name will pull up the plants you're searching for. 

You can also search by type. For example, if you type "Japanese" into the search bar, you will have a selection of catalogued Japanese plants to choose from.