Coast Live Oak
Quercus agrifolia
The Coast Live Oak is a picturesque branching oak, reaching a height of 10-25 meters. The appearance of the coast live oak can vary greatly, depending primarily on age. Younger trees are often stubby, with smooth pale gray bark and a narrow, denser crown. Older specimens have thick, roughly fissured trunks often covered in knots, lichens, and mosses. Their branches tend to be more defined with age, as leaf density decreases. The dark green evergreen leaves are oval-shaped and often curl down around the edges, hiding the sharp spiny teeth. Each leaf is 2-7 cm long and 1-4 cm broad. The reddish male flowers bloom on drooping catkins 5-10 cm long, while the less conspicuous female flowers, only .5 cm long, grow in clusters of 1-3. The slender green acorn, which matures to a reddish brown, is 2-3.5 cm long and 1-1.5 cm broad.
Basic Information
Member of the Fagaceae, or beech, family
Evergreen oak
Can live over 250 years
There are two recognized varieties:
Quercus agrifolia var. oxyadenia — found throughout range
Quercus agrifolia var. agrifolia — Southwesternmost California (San Diego area) south to Baja California
Can hybridize with the interior live oak (Q. wislizenii) and Shreve oak (Q. parvula var. shrevei)
Habitat
Native to from Mendocino County south to northern Baja California, remaining west of the Sierra Nevada mountain range
Commonly found in chaparral, mixed woodland, coastal hills and plains, rocky slopes
The Coast Live Oak is one of the only California native oaks to thrive in the coastal environment, although it is rare on the immediate shore
Ecological Role
Coast Live Oaks fertilize the soil around them over time with their own leaves and by building mycorrhizal fungus in the soil. Ultimately, they become islands of natural fertility that improve the health of the nearby plants.
Mycorrhizal fungus forms symbiotic relationships with 95% of all plants, helping provide them with water, minerals, and energy in exchange for the plant’s surplus energy
Attracts over 30 species of birds including the Oak Titmouse, Western Scrub Jay, Steller's Jay, and Chestnut-backed Chickadee
Host plant for a number of moths and butterflies including: California Sister, Propertius Duskywing, Mournful Duskywing, Golden Hairstreak, and Gold-Hunter's Hairstreak
Only known foodplant of Chionodes vanduzeei caterpillars
The California oak moth (Phryganidia californica) caterpillar subsists entirely on the leaves of the Coast Live Oak
In 8–10 year cycles, the caterpillar population is large enough to entirely denude healthy trees; however, trees recover, and botanists even think that the species provide mutual benefit, possibly in the form of fertilizer for the oak
Relatively tolerant of wildfires, as it can resprout from its root crown
Reproduction
Blooms from March-May
Monoecious, with male and female flowers on the same tree
Acorns mature about 7-8 months after pollination, in fall
Alternative Names
Brummit Fir, Douglas spruce, Oregon pine, Columbian Pine, Douglas pine, Pudget Sound pine, red fir
The Coast Salish name in the Halkomelem language is lá:yelhp.
In the Lushootseed language, the tree is called čəbidac
Historical Uses
At least twelve different Native American tribes consumed the acorns, which were a dietary staple
After removing the shells, the white inside was ground into a meal, which was washed to remove the bitter taste, and boiled into mush or baked in ashes as bread
Acorns could be stored for a long time, making them an ideal food source; the leaves of the Bay Laurel were sometimes placed in stores to prevent mosquitoes from infesting the acorns
The Cahuilla also used the acorns for children’s games, instruments, and animal bait
The bark and wood was often used for fire
The Mahuna used the plant to treat newborns with naval bleeds
The Diegueno used a decoction of the chipped bark to wash sores
Additional Information
The Douglas fir is the second tallest conifer in the world, behind only the Coast Redwood
The tallest recorded tree was 393 feet tall
Prior to massive logging, Douglas firs often grew over 300 ft tall, though some ~1000-year-old titans like surpassed 400 ft in height
Douglas-fir may have been the tallest tree species on the planet; however, so many trees were lost to logging that it is impossible to know now
The tree trunk can reach a diameter 4.5-6 meters, or 15-20 feet
best timber-producing species in North America, yielding more timber than any other species on the continent
Many of the oldest stands of Douglas fir have been ravaged by logging, resulting in massive loss of habitat and ecosystem devastation
The few remaining patches of rapidly shrinking old growth are not large enough to support the animals and plants that previously relied on them
