Quercus turbinella |
Quercus toumeyi |
|
---|---|---|
grey oak, shrub live oak, Sonoran scrub oak, turbinella oak |
Toumey oak, Toumey's oak |
|
Habit | Shrubs or small trees, evergreen or subevergreen, to 4 m. Bark light gray or brown, scaly. | Shrubs or small trees, deciduous or subevergreen. |
Bark | dark gray to almost black, scaly. |
|
Twigs | brown to gray, 1-3 mm diam., usually tomentulose, sometimes glabrous, becoming glabrate. |
brownish, 1-2 mm, usually persistently pubescent. |
Buds | brown, round to ovoid, 1-2 mm, minutely pubescent. |
reddish brown, ovoid, ca. 1 mm. |
Leaves | 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. |
blade oblong-elliptic or lanceolate, 15-25(-30) × (6-)8-12(-15) mm, base obtuse or cuneate, rarely subcordate, margins strongly cartilaginous, entire, sometimes sparsely mucronate-dentate toward apex, secondary veins 7-8 on each side, apex acute, sometimes rounded; surfaces abaxially dull gray, microscopically pubescent with long, soft, white or yellow hairs concentrated in tufts along midvein and base, adaxially glossy green, sparsely minutely stellate-pubescent or glabrate. |
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. |
solitary or paired, subsessile or on peduncle 2 mm; cup cup-shaped, 6 mm deep × ca. 8-9 mm wide, enclosing ca. 1/3 nut, scales moderately tuberculate; nut light brown, narrowly ovoid or elliptic, 8-15 × 6-8 mm. |
Cotyledons | distinct. |
distinct. |
Quercus turbinella |
Quercus toumeyi |
|
Phenology | Flowering spring. | Flowering spring. |
Habitat | Dry desert slopes, often in juniper and pinyon woodlands | Rocky slopes, oak woodlands, and open chaparral |
Elevation | 800-2000 m (2600-6600 ft) | 1500-1800 m (4900-5900 ft) |
Distribution |
AZ; CA; CO; NM; NV; TX; UT; Mexico (Baja California, Sonora, and probably n Chihuahua)
|
AZ; NM; TX; Mexico (Chihuahua and Sonora)
|
Discussion | 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. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Quercus toumeyi, particularly the more spinescent-leaved form, is often confused with Q. turbinella. The latter species has acorns on peduncles greater than 10 mm, and more or less evenly distributed minute, flat, stellate trichomes on the abaxial leaf surface, in contrast to the subsessile acorns and longer straight hairs along the midvein of the abaxial leaf surface in Q. toumeyi. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 3. | FNA vol. 3. |
Parent taxa | Fagaceae > Quercus > sect. Quercus | Fagaceae > Quercus > sect. Quercus |
Sibling taxa | ||
Synonyms | Q. dumosa var. turbinella, Q. subturbinella | Q. hartmanii |
Name authority | Greene: Ill. W. Amer. Oaks 1: 37. (1889) | Sargent: Gard. & Forest 8: 92. (1895) |
Web links |