The leaf of a fern grows from the rhizome directly, and is referred to as a frond, which typically contains a stipe (i.e. leaf stalk) and an expanded blade/lamina. The main axis of the blade is referred as a rachis. The young developing fronds show circinate vernation and thus are named as crozier or fiddlehead.

The blade of a fern is often dissected or divided. The leaflet at the first division of a pinnate leaf is a pinna (plural: pinnae) and its main axis is a pinna rachis. The leaflet at the second division is called a pinnule.