Quercus lobata

Quercus lobata, commonly called the valley oak or roble, is a deciduous oak endemic to California. It is among the largest North American oaks, sometimes exceeding 100 ft in height and developing a broad, spreading crown. It grows in interior valleys and foothills from Siskiyou to San Diego counties, where it is a characteristic species of valley oak woodlands, savannahs and riparian forests. Mature trees have extensive root systems, including deep tap roots capable of reaching buried soil moisture to help it survive California's long, dry Mediterranean summers. It can live for hundreds of years. The species is classified as Near Threatened by the IUCN as much of its former habitat has been converted to agriculture and urban development, and successful recruitment of young trees is limited in many populations. It has deeply lobed leaves and long, slender acorns.