FNA: Quercus havardii vs. Quercus turbinella

	Quercus havardii	Quercus turbinella
	Havard oak, Havard's oak, Havard's shinnery oak, sand shinnery oak, sand shinoak, shinnery oak	grey oak, shrub live oak, Sonoran scrub oak, turbinella oak
Habit	Shrubs, deciduous, low, forming clones 0.3-1.5 × 10 m, rhizomatous.	Shrubs or small trees, evergreen or subevergreen, to 4 m. Bark light gray or brown, scaly.
Bark	light gray, scaly-papery.
Twigs	brown or grayish, 1-2.5 mm diam., glabrous or densely short grayish or yellowish tomentulose, glabrate in age.	brown to gray, 1-3 mm diam., usually tomentulose, sometimes glabrous, becoming glabrate.
Buds	dark red-brown, subglobose, ca. 2 mm, sparsely pubescent.	brown, round to ovoid, 1-2 mm, minutely pubescent.
Leaves	blade green, often turning brownish with age, polymorphic, oblong or elliptic or sometimes lanceolate to oblanceolate or ovate to obovate, (30-)50-100 × (10-)20-50 mm, rather thick and hard, base rounded to cuneate, margins flat to revolute, at least some undulate, 2-3 rounded teeth on each side, secondary veins 5-8 on each side, much branched, apex broadly rounded, rarely acute; surfaces abaxially densely grayish or yellowish tomentulose or stellate-pubescent, sometimes only sparsely pubescent, secondary veins quite prominent, adaxially lustrous, very sparsely stellate-pubescent or glabrate, secondary veins very slightly if at all raised.	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 paired, subsessile or on peduncle to 10(-18) mm; cup from deeply cup-shaped to goblet-shaped, 10-12 mm deep × 15-25 mm wide, enclosing 1/3-1/2 nut, base rounded or slightly constricted, margin very thin and smooth, scales reddish brown, triangular-ovate to long-acute, proximally moderately to markedly tuberculate, pubescent, often canescent, tips loosely appressed; nut brown, ovoid, 12-25 × 14-18 mm.	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.	distinct.

	Quercus havardii	Quercus turbinella
Phenology	Flowering spring.	Flowering spring.
Habitat	Deep, shifting or stabilized sand dunes, off deep sands in putative hybrid populations	Dry desert slopes, often in juniper and pinyon woodlands
Elevation	500-1500 m (1600-4900 ft)	800-2000 m (2600-6600 ft)
Distribution	NM; OK; TX [WildflowerSearch map] [BONAP county map]	AZ; CA; CO; NM; NV; TX; UT; Mexico (Baja California, Sonora, and probably n Chihuahua) [WildflowerSearch map] [BONAP county map]
Discussion	Individual clones emerging to heights of 2-3 m from thickets occur sporadically across the Texas range of Quercus havardii and express some characteristics of Q. stellata, such as more deeply lobed leaves and smaller acorns. Such putative hybrids increase in frequency in the eastern part of the range of the species. Material of Quercus havardii from the Navajo Basin of Utah and adjacent Arizona has been treated as Q. havardii var. tuckeri Welsh. Welsh followed J. M. Tucker (1970) and interpreted these intermediate populations as putative hybrids between Q. havardii and both Q. turbinella and Q. gambelii. Giving varietal rank, instead of nothospecies status, to such populations seems arbitrary, and it certainly is inconsistent with their putative hybrid origins. (Discussion copyrighted by Flora of North America; reprinted with permission.)	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.)
Source	FNA vol. 3.	FNA vol. 3.
Parent taxa	Fagaceae > Quercus > sect. Quercus	Fagaceae > Quercus > sect. Quercus
Sibling taxa	Q. acerifolia, Q. agrifolia, Q. ajoensis, Q. alba, Q. arizonica, Q. arkansana, Q. austrina, Q. berberidifolia, Q. bicolor, Q. boyntonii, Q. buckleyi, Q. carmenensis, Q. chapmanii, Q. chihuahuensis, Q. chrysolepis, Q. coccinea, Q. cornelius-mulleri, Q. depressipes, Q. douglasii, Q. dumosa, Q. durata, Q. ellipsoidalis, Q. emoryi, Q. engelmannii, Q. falcata, Q. fusiformis, Q. gambelii, Q. garryana, Q. geminata, Q. georgiana, Q. graciliformis, Q. gravesii, Q. grisea, Q. hemisphaerica, Q. hinckleyi, Q. hypoleucoides, Q. ilicifolia, Q. imbricaria, Q. incana, Q. inopina, Q. intricata, Q. john-tuckeri, Q. kelloggii, Q. laceyi, Q. laevis, Q. laurifolia, Q. lobata, Q. lyrata, Q. macrocarpa, Q. margarettae, Q. marilandica, Q. michauxii, Q. minima, Q. mohriana, Q. montana, Q. muehlenbergii, Q. myrtifolia, Q. nigra, Q. oblongifolia, Q. oglethorpensis, Q. pacifica, Q. pagoda, Q. palmeri, Q. palustris, Q. phellos, Q. polymorpha, Q. prinoides, Q. pumila, Q. pungens, Q. robur, Q. robusta, Q. rubra, Q. rugosa, Q. sadleriana, Q. shumardii, Q. similis, Q. sinuata, Q. stellata, Q. tardifolia, Q. texana, Q. tomentella, Q. toumeyi, Q. turbinella, Q. vacciniifolia, Q. vaseyana, Q. velutina, Q. viminea, Q. virginiana, Q. wislizenii	Q. acerifolia, Q. agrifolia, Q. ajoensis, Q. alba, Q. arizonica, Q. arkansana, Q. austrina, Q. berberidifolia, Q. bicolor, Q. boyntonii, Q. buckleyi, Q. carmenensis, Q. chapmanii, Q. chihuahuensis, Q. chrysolepis, Q. coccinea, Q. cornelius-mulleri, Q. depressipes, Q. douglasii, Q. dumosa, Q. durata, Q. ellipsoidalis, Q. emoryi, Q. engelmannii, Q. falcata, Q. fusiformis, Q. gambelii, Q. garryana, Q. geminata, Q. georgiana, Q. graciliformis, Q. gravesii, Q. grisea, Q. havardii, Q. hemisphaerica, Q. hinckleyi, Q. hypoleucoides, Q. ilicifolia, Q. imbricaria, Q. incana, Q. inopina, Q. intricata, Q. john-tuckeri, Q. kelloggii, Q. laceyi, Q. laevis, Q. laurifolia, Q. lobata, Q. lyrata, Q. macrocarpa, Q. margarettae, Q. marilandica, Q. michauxii, Q. minima, Q. mohriana, Q. montana, Q. muehlenbergii, Q. myrtifolia, Q. nigra, Q. oblongifolia, Q. oglethorpensis, Q. pacifica, Q. pagoda, Q. palmeri, Q. palustris, Q. phellos, Q. polymorpha, Q. prinoides, Q. pumila, Q. pungens, Q. robur, Q. robusta, Q. rubra, Q. rugosa, Q. sadleriana, Q. shumardii, Q. similis, Q. sinuata, Q. stellata, Q. tardifolia, Q. texana, Q. tomentella, Q. toumeyi, Q. vacciniifolia, Q. vaseyana, Q. velutina, Q. viminea, Q. virginiana, Q. wislizenii
Synonyms		Q. dumosa var. turbinella, Q. subturbinella
Name authority	Rydberg: Bull. New York Bot. Gard. 2: 213. (1901)	Greene: Ill. W. Amer. Oaks 1: 37. (1889)
Web links	WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: CA Local Web sites: CalFlora, CalPhotos, SW CO Wildflowers WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Quercus turbinella

Havard oak, Havard's oak, Havard's shinnery oak, sand shinnery oak, sand shinoak, shinnery oak

grey oak, shrub live oak, Sonoran scrub oak, turbinella oak

Habit

Shrubs, deciduous, low, forming clones 0.3-1.5 × 10 m, rhizomatous.

Shrubs or small trees, evergreen or subevergreen, to 4 m. Bark light gray or brown, scaly.

Bark

light gray, scaly-papery.

Twigs

brown or grayish, 1-2.5 mm diam., glabrous or densely short grayish or yellowish tomentulose, glabrate in age.

brown to gray, 1-3 mm diam., usually tomentulose, sometimes glabrous, becoming glabrate.

Buds

dark red-brown, subglobose, ca. 2 mm, sparsely pubescent.

brown, round to ovoid, 1-2 mm, minutely pubescent.

Leaves

blade green, often turning brownish with age, polymorphic, oblong or elliptic or sometimes lanceolate to oblanceolate or ovate to obovate, (30-)50-100 × (10-)20-50 mm, rather thick and hard, base rounded to cuneate, margins flat to revolute, at least some undulate, 2-3 rounded teeth on each side, secondary veins 5-8 on each side, much branched, apex broadly rounded, rarely acute;

surfaces abaxially densely grayish or yellowish tomentulose or stellate-pubescent, sometimes only sparsely pubescent, secondary veins quite prominent, adaxially lustrous, very sparsely stellate-pubescent or glabrate, secondary veins very slightly if at all raised.

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 paired, subsessile or on peduncle to 10(-18) mm;

cup from deeply cup-shaped to goblet-shaped, 10-12 mm deep × 15-25 mm wide, enclosing 1/3-1/2 nut, base rounded or slightly constricted, margin very thin and smooth, scales reddish brown, triangular-ovate to long-acute, proximally moderately to markedly tuberculate, pubescent, often canescent, tips loosely appressed;

nut brown, ovoid, 12-25 × 14-18 mm.

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.

Quercus havardii

Quercus turbinella

Phenology

Flowering spring.

Habitat

Deep, shifting or stabilized sand dunes, off deep sands in putative hybrid populations

Dry desert slopes, often in juniper and pinyon woodlands

Elevation

500-1500 m (1600-4900 ft)

800-2000 m (2600-6600 ft)

Distribution

NM; OK; TX

[WildflowerSearch map]

[BONAP county map]

AZ; CA; CO; NM; NV; TX; UT; Mexico (Baja California, Sonora, and probably n Chihuahua)

[WildflowerSearch map]

[BONAP county map]

Discussion

Individual clones emerging to heights of 2-3 m from thickets occur sporadically across the Texas range of Quercus havardii and express some characteristics of Q. stellata, such as more deeply lobed leaves and smaller acorns. Such putative hybrids increase in frequency in the eastern part of the range of the species.

Material of Quercus havardii from the Navajo Basin of Utah and adjacent Arizona has been treated as Q. havardii var. tuckeri Welsh. Welsh followed J. M. Tucker (1970) and interpreted these intermediate populations as putative hybrids between Q. havardii and both Q. turbinella and Q. gambelii. Giving varietal rank, instead of nothospecies status, to such populations seems arbitrary, and it certainly is inconsistent with their putative hybrid origins.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

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.)

Source

FNA vol. 3.

Parent taxa

Fagaceae > Quercus > sect. Quercus

Sibling taxa

Q. acerifolia, Q. agrifolia, Q. ajoensis, Q. alba, Q. arizonica, Q. arkansana, Q. austrina, Q. berberidifolia, Q. bicolor, Q. boyntonii, Q. buckleyi, Q. carmenensis, Q. chapmanii, Q. chihuahuensis, Q. chrysolepis, Q. coccinea, Q. cornelius-mulleri, Q. depressipes, Q. douglasii, Q. dumosa, Q. durata, Q. ellipsoidalis, Q. emoryi, Q. engelmannii, Q. falcata, Q. fusiformis, Q. gambelii, Q. garryana, Q. geminata, Q. georgiana, Q. graciliformis, Q. gravesii, Q. grisea, Q. hemisphaerica, Q. hinckleyi, Q. hypoleucoides, Q. ilicifolia, Q. imbricaria, Q. incana, Q. inopina, Q. intricata, Q. john-tuckeri, Q. kelloggii, Q. laceyi, Q. laevis, Q. laurifolia, Q. lobata, Q. lyrata, Q. macrocarpa, Q. margarettae, Q. marilandica, Q. michauxii, Q. minima, Q. mohriana, Q. montana, Q. muehlenbergii, Q. myrtifolia, Q. nigra, Q. oblongifolia, Q. oglethorpensis, Q. pacifica, Q. pagoda, Q. palmeri, Q. palustris, Q. phellos, Q. polymorpha, Q. prinoides, Q. pumila, Q. pungens, Q. robur, Q. robusta, Q. rubra, Q. rugosa, Q. sadleriana, Q. shumardii, Q. similis, Q. sinuata, Q. stellata, Q. tardifolia, Q. texana, Q. tomentella, Q. toumeyi, Q. turbinella, Q. vacciniifolia, Q. vaseyana, Q. velutina, Q. viminea, Q. virginiana, Q. wislizenii

Q. acerifolia, Q. agrifolia, Q. ajoensis, Q. alba, Q. arizonica, Q. arkansana, Q. austrina, Q. berberidifolia, Q. bicolor, Q. boyntonii, Q. buckleyi, Q. carmenensis, Q. chapmanii, Q. chihuahuensis, Q. chrysolepis, Q. coccinea, Q. cornelius-mulleri, Q. depressipes, Q. douglasii, Q. dumosa, Q. durata, Q. ellipsoidalis, Q. emoryi, Q. engelmannii, Q. falcata, Q. fusiformis, Q. gambelii, Q. garryana, Q. geminata, Q. georgiana, Q. graciliformis, Q. gravesii, Q. grisea, Q. havardii, Q. hemisphaerica, Q. hinckleyi, Q. hypoleucoides, Q. ilicifolia, Q. imbricaria, Q. incana, Q. inopina, Q. intricata, Q. john-tuckeri, Q. kelloggii, Q. laceyi, Q. laevis, Q. laurifolia, Q. lobata, Q. lyrata, Q. macrocarpa, Q. margarettae, Q. marilandica, Q. michauxii, Q. minima, Q. mohriana, Q. montana, Q. muehlenbergii, Q. myrtifolia, Q. nigra, Q. oblongifolia, Q. oglethorpensis, Q. pacifica, Q. pagoda, Q. palmeri, Q. palustris, Q. phellos, Q. polymorpha, Q. prinoides, Q. pumila, Q. pungens, Q. robur, Q. robusta, Q. rubra, Q. rugosa, Q. sadleriana, Q. shumardii, Q. similis, Q. sinuata, Q. stellata, Q. tardifolia, Q. texana, Q. tomentella, Q. toumeyi, Q. vacciniifolia, Q. vaseyana, Q. velutina, Q. viminea, Q. virginiana, Q. wislizenii

Synonyms

Q. dumosa var. turbinella, Q. subturbinella

Name authority

Rydberg: Bull. New York Bot. Gard. 2: 213. (1901)

Greene: Ill. W. Amer. Oaks 1: 37. (1889)

Web links

Local floras: CA
Local Web sites: CalFlora, CalPhotos, SW CO Wildflowers
WildflowerSearch
iNaturalist (observations)
USDA Plants Database
LBJ Wildflower Center
SEINet
Plants of the World Online
Encyclopedia of Life
Wikipedia
Google Image Search

Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).

Choose a data source: Flora of North America

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Flora of North America species comparison

Quercus havardii

Quercus turbinella

Quercus havardii

Quercus turbinella