Juglans "J. regia", "Juglans" x Paradox, are widely used as rootstocks for "J. regia" cultivars because of their resistance to Phytophthora and to a very limited degree, the oak root fungus. However, trees grafted on these rootstocks often succumb to black line. In some countries, immature nuts in their husks are preserved in vinegar. In the UK, these are called pickled walnuts and this is one of the major uses for fresh nuts from the small scale plantings. In Armenian cuisine, unripe walnuts, including husks, are preserved in sugar syrup and eaten whole. In Italy, liqueurs called Nocino and Nocello are
Fruit (slang) presently defined as male testicles from the Cockney rhyming slang "cobbler's awls", meaning "balls" and "blow" was the blossoming of a fruit tree and is widely used as the Polari definition for oral sex on a man causing him to "blow"(ejaculate). "Fruitcakes", which are cakes containing both fruit and nuts, have been in existence since the Middle Ages, but it is unclear when the term started being used disparagingly, especially in the United Kingdom and the United States, as a slur for a 'crazy person' (e.g. "he's a complete fruitcake") although "Cassell's Dictionary of Slang" traces uses of "fruitcake" meaning