Sonoran Scrub Oak
Quercus turbinella

Family: Fagaceae

OTHER COMMON NAMES
Spanish: encinillo

CHARACTERISTICS
This plant is an evergreen shrub or small tree, reaching 10-15’ tall and slightly wider. While this is an evergreen species, many native evergreen oaks will hang onto old leaves and even have lots of brown leaves in spring just before the new leaves push out and then they drop the old leaves. Somewhat inconspicuous flowers occur in spring, followed by conspicuous acorns that ripen during monsoon. This oak reproduces sexually via its acorns if there is enough moisture present, but more often it reproduces vegetatively by sprouting from its rhizome and root crown.

LANDSCAPE USE
This is a good shrub or screen. This is one of the best oaks for low elevations.

Photo by Ries Lindley, SEINET
Quercus turbinella on iNaturalist

GROWING CONDITIONS
AN EXPLANAITION OF TERMS USED

SUN in low desert, give afternoon shade while young, can take full sun when mature or at higher elevations
WATER moderate to low
SOIL tolerant, but good drainage and amendment are recommended
HARDINESS hardy to -10°F
BASIN middle
CONTAINER not recommended
NUTRITION moderate to low
MAINTENANCE very little, remove dead branches in spring

ECOLOGY
Flowers in spring with inconspicuous, wind-pollinated flowers. Acorns ripen in fall. Oaks are wildlife keystone species hosting a mind-boggling number of insects. This brings in a vast array of substrate-insectivorous birds (birds that spend their time on these trees eating the insects). The acorns are important food for many birds and mammals (and some species eaten by people). The trees also provide important habitat for many birds and mammals. Almost all the oaks host a multitude of moths and butterflies including the following species:

Mexican-M Hairstreak (Parrhasius moctezuma)

Arizona Sister (Adelpha eulalia)

Short-tailed Skipper (Zestusa dorus)

Arizona Dull Firetip (Apyrrothrix araxes ssp. arizonae)

Burgess’s Sleepy Duskywing (Erynnis brizo ssp. burgessi)

Clitus Duskywing (Erynnis juvenalis ssp. clitus)

Meridian duskywing (Erynnis meridianus ssp. meridianus)

Scudder's Duskywing (Erynnis scudderi)

Mournful Duskywing (Erynnis tristis)

Oaks also host a diversity of insects that cause growths called “galls”. Galls are protective nests for the larvae of various insects (mostly tiny stingless wasps) to develop protected from pests. The have a diversity of shapes from giant ball-like growths, to small growths, on leaves or young stems. These galls do not harm healthy trees. Emory oaks that grow in riparian zones and get really tall are a favorite nesting site for owls and other raptors.

Oaks attract numerous other insects which, in turn, attracts canopy-gleaning birds.

ETHNOBOTANY
Sonoran Scrub Oak isused for food, tools and other purposes by southwestern United States indigenous peoples. The acorns need a considerable amount of treatment before they are edible.

NATURAL DISTRIBUTION
Found on arid slopes, often among chaparral communities, from 2,000-8,000’ in the southwestern United States and adjacent Mexico.

TAXONOMY AND NAME
This plant is in the family Fagaceae, the beech family. There are 627 accepted species in the genus Quercus widely distributed in the northern hemisphere.
The genus "Quercus" is from Latin, meaning "oak", and the name turbinella means "like a little top," refers to the acorns. We have many species of Quercus in our region.