Juglans regia variations in fatty acid content of the nuts: Walnuts and other tree nuts are important food-allergen sources that have the potential to be associated with life-threatening, IgE-mediated allergic reactions in some individuals. Certain extracts of walnuts have "in vitro" antioxidant and antiproliferative activity due to a high phenolic content. "Juglans regia" is used to treat Diabetes mellitus symptoms in Austrian traditional medicine, whereby air-dried leaves are used as aqueous decoction or liquor preparation and are consumed on a daily basis. In Skopelos, a Greek island in the Aegean Sea, local legend suggests whoever plants a walnut tree will die as
Juglans hindsii ("Quercus" spp.) and Fremont cottonwood ("Populus fremontii") trees. "Juglans hindsii" has only one confirmed native stand remaining. It is listed as Seriously Endangered on the California Native Plant Society Rare Plant Inventory. The IUCN classification is a Vulnerable species. It is threatened by hybridization with orchard trees, urbanization, and habitat conversion to agriculture. "Juglans hindsii" is a medium-sized tree of short bulky proportions. It grows up to tall, has a single erect trunk, commonly without branches for , and a crown that can be wider than the tree is tall. Trunks commonly reach in diameter near the base of the