Linked from
The 10 pages that link to Nut (fruit), each with the reason it gives.
BetulaceaeRelated: Hazelnuts and several other Betulaceae fruits are nuts in the botanical sense.
CupuleRelated: Many cupules surround nuts, but the cupule is separate from the nut's fruit wall.
FagalesRelated: Several Fagales produce nuts, including hazelnuts, beechnuts, and walnuts.
Carya laciniosaRelated: Its edible seed is enclosed in a thick-walled hickory nut.