Oak Tree Species ID & Ecology



Blue oak imageScientific name Quercus douglasii Hook. & Arn.

Common names Blue, white, mountain, rock, iron, post, jack, Douglas

Height Usually 20-60 ft.; tallest over 90 ft.

Mature Tree DBH (Diam. at Breast Ht.) Less than 1 ft., up to 2 ft.; largest over 6 ft

blue oak acorn Longevity Long-lived, 175-450 yrs.

Acorn Matures first year; variable in shape; warty scales; Cup very shallow

Shade Tolerance Seedlings not tolerant

Sprouting Variable sprouter; not vigorous on dry sites.

Sites Hot, dry sites with rocky soils, 12-40 in. deep; can’t compete with live oak on better sitesblue oak leaf 

Foliage Deciduous; blue-gray color; smooth or slightly to deeply lobed edges; 1-3 in. long and 1/2-2 in. wide.

Fire Tolerance Tolerates grass fires; not hot brush fires

Elevation 500-2000 ft. in north; up to 5000 ft. in south

356 year old Blue Oak Round from SLO County

Associates Grades into open valley oak stands at low elevations; blends into denser live oak stands at higher elev.; foothill pine common

Identification Notes Confused with valley oaks when leaves are dust

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Valley oakScientific name Quercus lobata Nee

Common names Valley, white, California white, mush, water, swamp, roble

Height 40 to 120 ft.

Mature Tree DBH (Diam. at Breast Ht.) 1-4 ft.; largest over 8 ft.

Longevity Long-lived, 200-250 yrs.

Valley oak acorn imageAcorn Matures first year, variable but large and tapered, cup over 1/3 of nut and warty

Shade Tolerance Seedlings somewhat tolerant, mature trees intolerant

Sprouting Not a vigorous sprouterVariable sprouter; not vigorous on dry sites

Sites Prefers fertile, well-drained bottomland soils, streambeds, and lower foothills

Valley oak leafFoliage Deciduous; leaves leathery with shiny, dark green-yellow above and grayish below; deep irregular lobes; 2-4 in.

Fire Tolerance Not tolerant of fires

Elevation 500-800 ft. in north; up to 5600 ft. in south

Associates Blue and Oregon white oak; sometimes interior live oak

Identification Notes Confused with Oregon white oak but acorns pointed with warty cups; Seedlings not tolerant

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Oregon White Oak imageScientific name Quercus garryana Dougl

Common names Garry oak, white oak, Oregon oak

Height 50 to 80 feet

Mature Tree DBH (Diam. at Breast Ht.) 2-3 ft.; largest over 5 ft.

Longevity 100-200 years

Oregon White Oak acornAcorn Matures first year; 1 in. long with shallow cup

Sprouting Excellent sprouter

Shade Tolerance Intermediate tolerance as seedling and intolerant as tree matures

Sites Cool humid sites near coast to hot, dry sites inland

Oregon White Oak leafFoliage Deciduous; 4-6 in. long; evenly and deeply lobed with rounded leaf tips; lustrous dark-green and shiny above and pale green below

Fire Tolerance Maintained in open stands by regular, low-intensity fires

Elevation 500-3000 ft.

Associates Douglas-fir and mixed evergreen forests; Pacific madrone and tanoak

Identification Notes Can be distinguished from valley oak by acorns

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Engelmann OakScientific name Quercus engelmannii Greene

Common names Engelmann, mesa

Height 20 to50 feet

Mature Tree DBH (Diam. at Breast Ht.) 1-2 feet

Longevity 100-200 years

Engelmann Oak leafFoliage Considered deciduous but foliage may persist during winter; similar toblue-gray color of blue oak

Acorn Matures first year

Sprouting Variable sprouter

Shade Tolerance Seedlings tolerant, mature trees intolerant

Sites Warm, dry fans and foothills

Engelmann Oak fireFire Tolerance Very tolerant of hot fires

Elevation Under 4000 feet

Associates In pure stands and with coast live oak

General Notes Very limited range in southern California makes protection a high priority

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Coast Live OakScientific name Quercus agrifolia Nee

Common names Coast live oak, California live oak, encina

Height 20 to 40 feet; may reach 80 feet

Mature Tree DBH (Diam. at Breast Ht.) 1-4 feet

Longevity Long-lived, 125 to 250 years

Coast Live Oak acornAcorn Matures first year; 3/4 to 2-3/4 in.; cup over 1/3 of nut and not warty

Sprouting Very vigorous sprouter

Shade Tolerance Shade tolerant throughout life

Sites Common on valley floors or not-too-dry fertile slopes

Coast Live Oak foliageFoliage Evergreen; 1-3 in.; roundish; dark and shiny above with gray or rusty fuzz underneath; cupped or spoon-shaped

Fire Tolerance Very tolerant of hot fires due to thick bark

Elevation Below 3000 ft. in north and up to 5000 ft. in south

Associates Forms pure stands; also grows with interior live oak and coast live oak

Identification Notes Confused with interior live oak but rounded and cupped leaves

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Interior Live OakScientific name Quercus wislizeni A. DC.

Common names Interior live oak, highland live oak, Sierra live oak

Height Usually 30-75 ft.; shrub form 8-10 ft.

Mature Tree DBH (Diam. at Breast Ht.) 1 to 3 feet

Longevity 150 to 200 years

Interior Live Oak acorn  Interior Live Oak acorn 2Acorn Matures second year; very slender, pointed, 1 in. long; cup over half the nut

Sprouting Very vigorous sprouter

Shade Tolerance Somewhat shade tolerant

Sites Wide range, from valleys to foothills; moister areas than blue oak

 Interior Live Oak leafFoliage Evergreen with smooth to very spiny-toothed; dark green above and lighter below with waxy/shiny surface; 1-4 in.; flat

Fire Tolerance Not very tolerant, but sprouts well after fire

Elevation Below 2000 feet in north and above 6200 feet in south

Associates In pure stands or mixed with blue and/or coast live oak, and valley oaks in So. California

Identification Notes Confused with coast live oaks; distinguished by flat leaves

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View Interior Live Oak Chaparral habitat information on CNPS website

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Canyon Live OakScientific name Quercus chrysolepis Liebm

Common names Canyon live oak, canyon oak, gold cup oak, live maul, maul oak, white live oak

Height 60 to 80 feet

Mature Tree DBH (Diam. at Breast Ht.) 1-4 ft; largest over 5 feet

Longevity Up to 300 years

Sprouting Variable sprouter

Acorn 1-1/2 in. long; thick, shallow cup

Canyon Live Oak foliage  Foliage Evergreen; 3 in. long; persist 3 or 4 seasons on tree; usually not lobed; leathery

Shade Tolerance Tolerant of shade

Fire Tolerance Sensitive to hot fires

Elevation 300 to 5000 feet

Associates Found with mixed conifer, chaparral, and woodland species; tanoak, Douglas-fir, Pacific madrone, coast live oak

Sites Most widely distributed oak in CA.; sheltered north slopes and steep canyons

Identification Notes Both a shrubby and tree form; very dense wood

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View Canyon Live Oak Chaparral habitat information on CNPS website

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California Black OakScientific name Quercus kelloggii Newb.

Common names Black, California black oak

Height 60 to 90 feet

Mature Tree DBH (Diam. at Breast Ht.) 1 to 4 feet

Longevity 100-200 yrs., occasionally up to 500 years

California Black Oak acornAcorn Matures second year; 1-1/2 in. long; thin cup over half the nut

Sprouting Excellent sprouter

Shade Tolerance Intermediate tolerance as seedling and intolerant as tree matures

Sites More common on forest sites; found on moister hardwood rangelands; well-drained soils

California Black Oak foliageFoliage Deciduous; 5 in. long; 5-7 lobed; spiny leaf tips; dark yellow-green above and pale yellow-green below

Fire Tolerance Very sensitive to cambium being killed in hot fires

Elevation 200 to 6000 feet

Associates Most common with tanoak, madrone, mixed conifer forest species;, also with coast live oak, interior live oak, and blue oak

General Notes Protected by Forest Practice Act on timberlands; commercial properties for finished lumber

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View California Black Oak Forest habitat information on CNPS website