Don't be confused by the various names: filberts, hazelnuts and cobnuts are all aliases for the same nut. Hazelnuts, ubiquitous as a coffee flavoring, a toasty oil or a chocolaty bread spread, hail from the hazel tree. No matter what you call them, they taste delicious as part of a nut mix or tossed into salads or rich pasta dishes.
What's in a Name?
The different names for the nut depend on where you're from. Hazelnut comes from the Anglo-Saxon word for cap, which the nut resembles. Filbert is an old-fashioned name for the nut, so-named by French settlers in Oregon -- where filberts, or hazelnuts, thrive. Cobnuts is the British term for the same nut. Many varieties of the hazel tree exist, and all yield a different version of the hazelnut. Regardless of the variety of the tree from which they come, the nuts may be called filberts or hazelnuts and can be used interchangeably in recipes.