Coast Live Oak

Description:

Coast Live Oak typically has a much-branched trunk and reaches a mature height of 10–25 meters. Some specimens may attain an age exceeding 250 years, with trunk diameters up to three or four meters, such as the magnificent specimens on the Filoli estate in San Mateo County. The trunk, particularly for older individuals, may be highly contorted, massive and gnarled. The crown is broadly rounded and dense, especially when aged 20 to 70 years; in later life the trunk and branches are more well defined and the leaf density lower. The leaves are dark green, oval, often convex in shape, 2–7 cm long and 1–4 cm broad; the leaf margin is spiny-toothed (spinose), with sharp thistly fibers that extend from the lateral leaf veins. The outer layers of leaves are designed for maximum solar absorption, containing two to three layers of photosynthetic cells. The flowers are produced in early-to-mid spring; the male flowers are pendulous catkins 5–10 cm long, the female flowers inconspicuous, less than 0.5 cm long, with 1-3 clustered together. The fruit is a slender reddish brown acorn 2-3.5 cm long and 1-1.5 cm broad, with the basal quarter enclosed in a cupule; unusually for a red oak, the acorns mature about 7–8 months after pollination (most red oak acorns take 18 months to mature).

Habitat:

Coast Live Oak is the only California native oak that actually thrives in the coastal environment, although it is rare on the immediate shore; it enjoys the mild winter and summer climate afforded by ocean proximity, and it is somewhat tolerant of aerosol-borne sea salt. The coastal fog supplies relief from the rainless California summer heat. It is the dominant overstory plant of the Coast Live Oak woodland habitat, often joined by California Bay Laurel and California Buckeye north of Big Sur. Associated understory plants include Toyon, various manzanitas and Western Poison-oak. Normally the tree is found on well drained soils of coastal hills and plains, often near year round or perennial streams. It may be found in several natural communities including Coast Live Oak woodland, Engelmann Oak woodland, Valley Oak woodland and both northern and southern mixed evergreen forests. While normally found within 100 kilometers of the Pacific Ocean at elevations less than 700 meters, in southern California it occasionally occurs at up to 1,500 meters in altitude.

Notes:

FOUND in Los Padres National Forest. HIstorical Usage: At least twelve distinct cultures of Native Americans are known to have consumed the acorns as a dietary staple. In the 18th century Spaniards in the San Fernando Valley used the wood for charcoal to fire kilns in making adobe. Later this form of charcoal would be utilized in the baking, gunpowder and electric power industries. In the 18th and 19th centuries shipbuilders sought out the odd angular branches to make special joints. Pioneers moving west would harvest small amounts for making farm implements and wagon wheels, but the greatest impact was the wholesale clearing of oak woodlands to erect sprawling cities such as San Diego and San Francisco. The irregular shape often let the tree escape widespread harvest for building timbers, and also led the early settlers to endow the Coast Live Oak with mystical qualities. Its stateliness has made it a subject of historical landscape painters throughout California modern history since the mid-19th century.