Characteristic beak. Striking. The Leather Oak is growing on serpentine soil, past the end of the maintained trail: Irene Brown Trail (Trail b). Irene explored through this serpentine, making a way later followed by John Rawlings and other botanists. Thanks to John for pointing this out, and to Merav Vonshak for the nice gall brocure. Jasper Ridge Biological Preserve, 8/21/2021, 8:24 am.