Arteria Leaf crafting materials can be a particularly rare item in the Elden Ring. Unlike flowers and fruit, leaves cannot be found in most of the greener areas of the game. Instead, players will need to travel to certain corners of the map to hunt it down. In turn, it can be used to craft items that primarily revolve around increasing your attack stats. This is where you can find the Arteria Leaf and the recipes you will make with it.
The fastest method to collect Arteria Leaves is to buy them from the Isolated Merchant on the west side of the Sweeping Peninsula. If you haven’t made it to the area yet, you can find an Arteria Leaf in the center of Limgrave’s Misty Forest Ruins. The material is on a burial ground (as shown above) that is filled with Poison Pods, so be careful how you approach it. There is also an area southwest of the Liurnia of the Lakes that holds two Arteria Cards – shown by the marker below. For reference, the material looks quite similar to the Erdleaf Flower, but it will emit a red light from its plants.
The most beneficial item the Arteria Card will help craft is the Uplifting Aromatic, a consumable that temporarily increases the attack power of you and any allies that may be near you. Better yet, it halves the enemy’s next attack you take. To unlock its recipe, you need to get the Perfume Cookbook first  at Altus Plateau’s Perfumers’ Ruins. Additionally, Arteria leaves are also used in recipes for Bloodboil Aromatic and Exalted Flesh. Both of these boost attack stats, but the Aromatic Bloodboil requires the use of FP.
https://www.gamepur.com/guides/where-to-find-arteria-leaf-in-elden-ring-and-what-it-does Where to find the Arteria Leaf in the Elden Ring – and what it does