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The precise identification of Oaks in the Four Corners area is a subject of much disagreement: the Flora of North America, A Utah Flora, Colorado Flora, Trees and Shrubs of Colorado, and the Synthesis often disagree on the presence or absence of a half dozen species -- except for the unanimous agreement about the ubiquitous Quercus gambelii and the fact that Q. gambelii hybridizes with just about any other Oak, producing a confusion of similar-looking plants.

The following photographs do show, however, a plant clearly not Quercus gambelii and I think we are quite safe in calling it Quercus turbinella even though some expert floras indicate that this species does not exist in our area.

As you hike the Four Corners states, take a careful look at Oaks and you will find leaf shape and tree height varying widely  --  the result of hybridizing.

Quercus turbinella

Quercus turbinella

Quercus turbinella
Quercus turbinella (Holly Oak)
Fagaceae (Beech Family)

Foothill. Shrublands. Spring.
Above: Lower Butler Wash, Utah, March 15, 2016 and April 20, 2017.
Left: Canyons of the Ancients National Monument, March 18, 2007.

Quercus turbinella occurs in all of the Four Corners states but is most common in Arizona and New Mexico (as the map below indicates).  It grows to about twenty feet tall but more commonly in its northern limits, as shown here, is a thick shrub in shape, about six feet by six feet.  It can be solitary, as it usually is in the Four Corners area, or it can form thickets, as in the above and last photographs. The thicket in the top photograph is about twenty feet long and eight feet high.

In the second photograph above, new light green spring growth is draped with male pollen chains and contrasts with the darker green of last year's growth in the Q. turbinella behind it.

"Turbinella" is from the Latin for "a little top" and perhaps refers to the shape of the long, narrow acorn.  Edward Greene named and described this tree in 1889.

Quercus turbinella
Quercus turbinella (Holly Oak)
Fagaceae (Beech Family)

Foothill. Shrublands. Spring.
Canyons of the Ancients National Monument, May 28, 2009.

Distinctive leaves are about a half inch wide and an inch long, much smaller than those of the very common Quercus gambelii.  They are pubescent with a number of stellate hairs (i.e., branched in a starburst shape) and they are sharply toothed, giving rise to the common name, "Holly Oak".  The leaves shown here are new; those above are hanging on the tree from the previous year.  Notice the dried pollen chains at the bottom of the photograph at left.

Quercus turbinella
Quercus turbinella (Holly Oak)
Fagaceae (Beech Family)

Foothill. Shrublands. Spring.
Behind the Rocks Wilderness Study Area, Moab, Utah, October 26, 2012.

In deep sandy dunes, Quercus turbinella spreads itself as a low, multi-stemmed shrub.  In the exact same area, where soils are more stable, the tree grows with a single main stem. Q. gambelii grows next to these plants and hybrids are numerous.

Range map © John Kartesz,
Floristic Synthesis of North America

State Color Key

Species present in state and native
Species present in state and exotic
Species not present in state

County Color Key

Species present and not rare
Species present and rare
Species extirpated (historic)
Species extinct
Species noxious
Species exotic and present
Native species, but adventive in state
Eradicated
Questionable presence

Range map for Quercus turbinella