Kola nut tree and Nut tree

Kola nut tree noun - Tree bearing large brown nuts containing e.g. caffeine; source of cola extract.

Nut tree and kola nut tree are semantically related. In some cases you can use "Nut tree" instead a noun phrase "Kola nut tree".

Nut tree noun - Tree bearing edible nuts.

Kola nut tree and nut tree are semantically related. Sometimes you can replace phrase "Kola nut tree" with "Nut tree", this phrases are similar.