Pickled walnuts used in recipes, commonly cooked in beef dishes. Pickled walnuts are made from the fruit of both common walnut tree varieties: "Juglans regia", the Persian, royal, English or common walnut, and "Juglans nigra", the black or American walnut. The first stage is to pick the walnuts whilst they are still green and before the shells have set. Most recipes say that late June is about the best time to pick them. The soft walnuts are then soaked in brine (salt water) for at least ten days. The walnuts are then drained and left to dry in the air. Soaking the
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