Quercus turbinella


Ill. W. Amer. Oaks 1: 37. 1889.

Common names: Sonoran scrub oak
Synonyms: Quercus dumosa var. turbinella (Greene) Jepson Quercus subturbinella Trelease
Treatment appears in FNA Volume 3.

Shrubs or small trees, evergreen or subevergreen, to 4 m. Bark light gray or brown, scaly. Twigs brown to gray, 1-3 mm diam., usually tomentulose, sometimes glabrous, becoming glabrate. Buds brown, round to ovoid, 1-2 mm, minutely pubescent. Leaves: petiole 1-4 mm. Leaf blade elliptic or ovate, (1.5-)20-30 × (5-)10-15(-20) mm, thick, leathery, base cordate or rounded, margins planar or slightly crisped-undulate, coarsely 3-5-toothed or very shallowly lobed on each side, teeth spinose with spines 1-1.5 mm, secondary veins 4-8 on each side, apex acute or obtuse; surfaces abaxially yellow or reddish, usually glaucous, minutely stellate-puberulent, adaxially grayish, glaucous, or yellowish glandular, glabrous or sparsely and minutely stellate-pubescent. Acorns solitary or several, on axillary peduncle 10-40 mm; cup hemispheric or shallowly cup-shaped, 4-6 mm deep × 8-12 mm wide, covering 1/4-1/2 nut, scales tightly appressed, ovate, moderately tuberculate, grayish or yellowish puberulent; nut light brown, ovoid, to 20 × 11 mm, minutely puberulent or glabrate. Cotyledons distinct.

Phenology: Flowering spring.
Habitat: Dry desert slopes, often in juniper and pinyon woodlands
Elevation: 800-2000 m


V3 1061-distribution-map.gif

Ariz., Calif., Colo., N.Mex., Nev., Tex., Utah, Mexico (Baja California, Sonora, and probably n Chihuahua).


Formerly, California populations of what here is referred to as Quercus john-tuckeri have been included in the concept of Q. turbinella. Quercus john-tuckeri has subsessile fruit and noncordate leaf bases as opposed to the consistently pedunculate fruit and strongly cordate leaf bases of Q. turbinella. The two species seem to be no more closely related to each other than each might be to other southwestern oaks, and Q. john-tuckeri shares at least as many characteristics with Q. berberidifolia as with Q. turbinella. Thus, treatment of these two taxa as varieties of the same species is inappropriate.

Quercus turbinella forms putative hybrid swarms with Q. gambelii (see treatment), as well as with Q. grisea.

Lower Taxa

... more about "Quercus turbinella"
Kevin C. Nixon +  and Cornelius H. Muller +
Greene +
Sonoran scrub oak +
Ariz. +, Calif. +, Colo. +, N.Mex. +, Nev. +, Tex. +, Utah +, Mexico (Baja California +, Sonora +  and and probably n Chihuahua). +
800-2000 m +
Dry desert slopes, often in juniper and pinyon woodlands +
Flowering spring. +
Ill. W. Amer. Oaks +
tucker1961a +
W1 +  and Illustrated +
Quercus dumosa var. turbinella +  and Quercus subturbinella +
Quercus turbinella +
Quercus sect. Quercus +
species +