Oaks in the Black Oak family such as the Coast Live Oak here, have a thatched patten on their acorn cup. White Oaks (eg Valley) have a knobby pattern -- and less tannin, makking them more preferred as food. (See below.) A bay nut completes the picture. Leaves echo the same plants. Jasper Ridge Biological Preserve, near Road C along Corte Madera Creek. 11/6/2022, 10:02 am.