General: Gambel Oak (Quercus gambelii) is a deciduous shrub or tree of the middle-elevation mountains with acorns (or at least acorn caps from last year) and 3- to 4-inch-long, lobed leaves with smooth edges (no spine on lobe tips). Compare with the leaves of Shrub Live Oak (Quercus turbinella). No other tree in our area has similarly lobed leaves.

Gambel Oak is an uncommon component of vegetation communities on middle-elevation mountain canyons and slopes in the Upper Sonoran (Pinyon-Juniper Woodland) and Transition (Yellow Pine Forest) life zones.

Family: Oak (Fagaceae).

Other Names: Scrub oak, oak brush, white oak, Gambel's Oak; Quercus turbinella.

Plant Form: Shrub or small tree. Generally occurs as shrub thickets at lower elevations, but more tree-like at higher elevations.

Height: 6 to 15 feet, sometimes to about 20 feet.

Bark: Bark gray or brown, scaly.

Stems: Twigs brown or reddish brown.

Leaves: Petiole about 1/2 inch long. Blade oval, to 4.5 inches, with 4-6 deep lobes. Dorsal surface glossy green, ventral surface pale and velvety. Lobes without spines. Deciduous.

Flowers: Blooms mid-late spring. Staminate inflorescences: catkins, slender, flowers many. Pistillate inflorescence among upper leaves. Staminate and pistillate flowers minute; no petals.

Seeds: Acorn, solitary or paired. Cap deeply cup-shaped, enclosing up to half of the acorn. Acorn green, aging to brown in 1 year.

Habitat: Moist mountain slopes, shady canyons, and ravines.

Elevation: 4,000 to 6,400 feet.

Distribution: Southwestern U.S. to Texas and south into Mexico.

Comments: Gambel oak hybridizes with other scrub oaks (including Shrub Live Oak), sometimes making identification difficult.