The Leaf tool can be used to produce a simple leaf shape, but it can also be used to construct many other interesting shapes. Like the Petal tool, it’s basically two line segments that both share the same endpoints but are stretched out by their Bezier points so that they don’t overlap exactly and look like one segment. On construction you can use the Bezier point option button which looks like this:

to control how many Bezier points are used when constructing the Leaf. You can then use all the Bezier point manipulation tools (Move Bezier Point tool, Reset Bezier Points tool, Change Bezier Point Number tool, etc.) and the Move Vertex tool to change its shape if you want. On construction you can also use the Drag Constraint button

to orient the leaf horizontally, vertically, or along a vector. Like the Petal tool, the Leaf tool also has one other construction option: sharp end or round end. This determines whether the leaf is “closed” at its initial point which will produce a rounded effect if the paint attributes allow it (if you’re using a rounded Join Style for instance). Under certain paint attribute settings, such as if you’re using a Stroke Style of FILL, you won’t notice a difference. See the Paint Attributes for more information. Here’s an example of a leaf construction: