13 Native Trees

Protected by the City Trees and Tree ProtectionOrdinance May 2002 Amendment

13Native Trees

California Black Walnut(Juglans californica)

This native tree is15-30 feet tall andfrequently has sev-eral trunks. Trunksof mature trees aredark brown. Manyseparate leaves, the same size andshape, grow along a stalk up to 11inches long; theyturn from brightgreen to yellowbefore falling off in the winter. The walnut is small,thick-shelled andwhen cracked openresembles the faceof an owl. Black walnuts, like acorns, were animportant food for indigenous people of Californiaand remain important for wildlife.

The May 2002

amendment to the City Trees

and Tree Protection Ordinance

created protection measures for

three types of trees on private

property — native, specimen, and

landmark. Native trees are specified

for protection because they help

maintain native populations of

birds, insects, and other animals,

and promote better environmental

conditions. The 13 native trees

that are protected in the amend-

ment are illustrated and described

in this brochure. To qualify for pro-

tection, native trees must have a

trunk diameter of 8 or more inches

at chest height. In residential

zones, the trees must be in a spec-

ified setback. On non-residential

properties, native trees are

protected on the entire site.

City of PasadenaCity of Pasadena

The brochure is intended as a general guide to identifying native trees. To determine thespecies on your property, please consult with a certified arborist.

Canyon Live Oak (Quercus chrysolepis)

The Canyon LiveOak is a variabletree adapted to the often dry, hot conditions inSouthernCalifornia. It cangrow in a shrubform in harsh hill-side conditions, orto heights of 70feet in open areas.The average canopy spread is 20-60 feet. Theleaves are bright, shiny green on top and bluishgray underneath; leaf edges can be spiny orsmooth. The bark tends to be smooth while thetree is young, but becomes rougher and grayishwith age. Besides its exceptionally strong hardwood, another feature is the large acorns thattake two years to mature and can be between 2 to 3 inches long. The scientific name “chrysolepis”means “gold scale” and comes from the tiny goldenhairs that cover the underside of the leaves andthe bumpy scales of the acorn cups.

Department of Public WorksParks and Natural Resources100 North Garfield Ave., Pasadena, CA 91109 (626)744-4321www.ci.pasadena.ca.us/publicworks click on tree ordinance

California Buckeye(Aesculus californica)

Like other native trees, the California Buckeye, or HorseChestnut, is adapted to Southern California’s dry climate.Its umbrella-like canopy spreads out to 30 feet, but itonly reaches heightsof 15-25 feet. Thepalm-shaped leavesinclude 5-7 leavesthat are oblong andpointed at the end.The large, light red or white flower clusters are attractiveand pungently scented, producingnectar that is deadlyto bees. In native settings, this treeloses its leaves inmidsummer; in cultivated areas, it retains them until late fall. Once the leaves fall, the large, pear-shaped seedpods are silhouetted against the silvery trunk and bare branches.

California Sycamore(Platanus racemosa)

Sycamores are stream-lovingnatives, reaching heights of 80feet with a canopy spread of 50 feet. The highly recogniza-ble bark sloughs off as the treegrows, displaying a patchwork of light and dark colors. Leavesare broad, deeply fingered andturn light brown/orange beforedropping in late fall and winter.Fruits of this tree are bristly brown balls comprised of manysmall, narrow seeds connected to tufts of “hair.” In natural settings, Sycamores survive dry periods by having deep rootsthat reach down to ground water. In landscape areas, theyneed supplemental water during droughts.

California Laurel(Umbellularia californica)

The Laurel is an evergreen treethat can grow 90 feet tall and 50feet wide. The dark green leavesare glossy on top, finely hairybeneath, 3-5 inches long andleathery. The bark is generallysmooth and reddish-brown. Theround, 1/2 to 1-inch berry isgreen when young, turning darkpurple when mature. Bay trees need steady access to water and grow naturally on canyon slopes and alongstreams. When rubbed or crushed, the leaves and twigs are distinctly aromatic and can cause itching in eyes. Leaves are not to be confused with the cultivated bay leaves that are used in cooking.

Black Cottonwood(Populus trichocarpa)

This tree is named afterthe dark color of its bark.The tallest nativeCottonwood, it reachesheights of 120 feet. Fastgrowing, Cottonwoodsrequire moist soil thatexists along streams andin flood plains. Leaves are heart-shaped and have smallserrated-like edges. They are dark green on top and palegreen underneath, turning bright yellow before droppingin the fall. The fruit is a round, brown capsule thatsplits open to release many cottony seeds that drift inthe breeze. Cottonwood leaves make a distinct rustlingsound in the wind.

Western Cottonwood(Populus fremontii)

This water-loving tree, also calledFremont Cottonwood, grows toheights of 80 feet and has abroad, open canopy. The trunk isgray with thick, rough bark. Thetriangular leaves are often widerthan long. They are shiny yellow-green during spring and summer,but turn bright yellow in the fall before dropping. Fruits arelight brown, egg-shaped capsules that open in the spring torelease many cottony seeds. Early settlers planted Cottonwoodsfor shade and windbreaks.

Arroyo Willow(Salix lasiolepis)

This tree is native tostreams where there is plenty of water, whichallows it to form adense root mass. It may look like a shrubin areas that have frequent scouringfloods; otherwise it can reach heights of35-40 feet with a 45-foot spread. ArroyoWillows frequentlyhave more than onetrunk that is smoothand gray-brown whenyoung, becomingdarker and rough with age. Leaves are oblong, darkgreen on top and silvery-white underneath, turning yellow-brown in summer and falling off in the winter.Large trees may look like they’re “weeping” because oftheir hanging branches and long leaves. In spring, thecottony seeds can be seen blowing from the tree.

Scrub Oak(Quercus berberidifolia)

This shrub-like Oak is adense growing, short,wide tree that may reachheights of 15 feet. Thisspecies usually grows like a shrub with manytrunks. The bark is generally gray, smooth when young and rough whenolder. The Scrub Oak has small, leathery leaves withspines on the edges and small, oval acorns with knobbycaps. This Oak is not common as a street tree inPasadena, but is abundant in Pasadena’s foothills andthe Arroyo Seco.

California WhiteOak/Valley Oak(Quercus lobata)

This majestic tree thrives indeep, rich soil and can reach a height of 150 feet, with aspread of 75-100 feet. Thename lobata denotes the leaf’sshape with 7-11 lobes. Leavesare glossy green in spring and summer, turning brown before falling in autumn. Valley Oakacorns are 1-2 inches long and chestnut brown. The bark isgray, thick and cracked. Legend says that when rainy wintersare approaching, Valley Oaks drop more acorns than usual.

Engelmann Oak(Quercus engelmannii)

Also known as thePasadena Oak, this is alarge, wide-spreadingevergreen tree. Thecanopy has an averageheight of 40-50 feet andcan be twice as wide. Ithas smooth, wavy-edgedleaves that are 2-3 inches in length and gray-blue incolor. The bark is light gray and furrowed. Acorns areround-tipped and half enclosed in bumpy caps. TheseOaks are adapted to Southern California’s dry climate but may lose some leaves during drought years.

White Alder(Alnus rhobifolia)

This is a fast-growing tree thatwill reach heights of 50-70 feet,with a canopy spread of 40 feet.It has one main trunk that isusually very straight and lightgray, white or light brown incolor. Branches that break offfrom the trunk leave scars thatresemble eyes. Alder leaves arebright green, triangle shaped andhave small teeth on the edges. The seeds are contained in tiny cones that are clustered on short stems. Alders need acontinuous water supply and grow naturally along streams in Pasadena’s canyons.

Coast Live Oak(Quercus agrifolia)

One of Pasadena’s most commonnative trees, the Coast Live Oakis highly recognizable by thedense canopy of small, cupped,dark green leaves that haveprickly points along the edges.Trunk bark is gray; smooth andlight colored in youth, rough and darker when mature. Theacorns are dark brown, thin and pointed. Coast Live Oaks aregenerally slow-growing trees that may reach 70 feet in heightwith a canopy of 100 feet or more and a root system about thesame size as the canopy. The trees drop some of their leaves inthe spring, while gradually gaining new leaves. Over 200 nativebird species rely on Coast Live Oaks for food and shelter.