VALLEY OAK

Species Name: Quercus lobata
Family: Fagaceae (oak family)
Plant Type: Broad-leaf tree



Description:  Tree, wide top, height 50-115 feet (often as wide), may have massive branches sometimes extending to the ground, largest North American oak, deciduous.



Leaf:  Length 2-4 inches, surface dark green, underside pale green with felt-like hairs, margin with 6-10 deep, rounded lobes.

 

Flower:  March-April, female flower tiny, singular or small clusters on new growth; male flower catkin, long, threadlike strand containing 25 - 100 male flowers, located on older growth.

Fruit/Seed:  Acorn:  long, conical, length to 2 inches (largest of California oaks), smooth interior, ripens in autumn after 1-year growth, germinates immediately.  Cap with wart-like bumps on scales.

Typical Location:  Established floodplain, valleys; elevations below 5,600 feet.

Revegetation Approach:  Container, direct seed.  Hybridizes with Q. berberidifolia, Q. corneliusmulleri, Q. douglasii, Q. engelmannii, Q. garryana, Q. john-tuckeri.

Key Notes:  Leaf and acorn morphology help distinguish from live oak (Q. agrifolia) and Oregon oak (Q. garryana).

Notes:  Trees provide roosts and nesting sites for cavity nesting birds and bats. Source of large woody debris. Acorns are an important food source for many wildlife species, especially woodpeckers and squirrels.  Young branches may have dense clusters of spherical insect galls harboring small, native wasp larvae.  Native Americans utilized acorns as a food crop.  May live for 400- 600 years.