Coastal Sage Scrub Oak

Coastal sage scrub oak (Quercus dumosa) is a small evergreen oak in the family Fagaceae, endemic to the California Floristic Province, occurring in fragmented populations across coastal and foothill areas of southern California and northern Baja California, Mexico. It grows in coastal sage scrub and chaparral communities on thin, rocky, or sandy soils, typically below 900 metres elevation. This shrubby oak rarely exceeds 2 metres and produces small, spiny-margined evergreen leaves and acorns that provide critical food for acorn woodpeckers, scrub jays, mule deer, and other wildlife. Quercus dumosa is assessed as Endangered by the IUCN, with its range having contracted severely due to urbanisation of the Southern California coast, fire suppression altering vegetation dynamics, invasive annual grasses, and prolonged drought associated with climate change. Many populations are now isolated fragments in remaining coastal sage scrub, one of the most threatened plant communities in North America. The species is protected under various Californian conservation plans, and seed banking and restoration planting efforts are ongoing to bolster declining populations.