Common Name: Coast Live Oak; California Live Oak, Encina

Scientific Name: Quercus agrifolia

Family: Fagaceae

Identification:

Habit:

-Slow-growing evergreen tree (typical age in cultivation ranges from 40-110 years)

-At maturity, height range is 25-80 ft. (8-25 m, in cultivation)

-At maturity, width range is 15-35 ft. (5-11 m, in cultivation)

-Branches tend to extend almost to ground level.

-Has round to broad and dense crown.

-Commonly has a densely branched trunk.

Leaves:

-Alternate leaf pattern

-Oval or rounded, convex (cupped downward) leaves

-Can grow up to 2 ½ in. (7 cm) long

-Short-stalked

-Hard and leathery texture

-Spine-tipped edges

-Smooth and shiny green on top of leaf

-Duller green and fuzz present on bottom of leaf.

Twigs and Bark:

-Twig commonly has a slender width.

-Twig has clustered end buds.

-Reddish brown twig color.

-Broad, rounded twig tips (buds).

-Bark is gray-brown when young and black and brown striped when mature.

-Bark becomes darker as it matures.

-Bark is smooth and develops light gray ridges as it matures.

Flowers and Fruits:

-Flowers have both male and female reproductive organs (monoecious).

-Male organs in 2-4 in. (5-10 cm) long, yellow-green drooping part of flower (catkin).

-Female organs found in red-green spike at leaf axis.

-Fruit produced is a light-brown acorn that are about ¼ enclosed in the cup.

-Thin cone-shape with an average length of 1-1 ½ in. (2.5-4 cm)

-Takes almost a year to mature (usually ripen during early fall).

Where it’s from:

Native range:

-Coastal California and Mexican native species

-Currently most commonly grows west of central California valleys.

-Furthest northern grows in Mendocino County, California.

-Furthest southern grows in northern Baja California, Mexico.

-Tree often found in valleys and near streams.

-Thrives in USDA Hardiness zones of 8-11 (minimum winter temp. of 10°F (-12°C)) 

 

Ecological notes:

-Coast Live Oak uses a deep taproot system that is commonly partnered with water-uptake-aiding soil fungi (mycorrhizae).

-Most acorns are dropped in fall, but some are dropped in spring to help avoid  consumption by birds and squirrels.

-Acorns usually germinate 15-50 days after falling (no dormancy requirement).

-Susceptible to Sudden Oak Death, a fungal disease.

What we use it for

-The cooked seed is considered a staple food source used by Native American Indian tribes. (dried or ground into powder to thicken stews)

-Galls on tree (abnormal growths sometimes found on tree; caused by larvae of insects) are very astringent (drying), and can be used to help treat hemorrhages and dysentery.

-Mulch produced from leaves helps repel slugs from soil.

-Buttons can be made from seed cups.

-catkin gall 

References

Image resources

Biographer:

Donald Johnson ‘21, FYS 20: Plants in Our World, Fall 2017.