FNA: Quercus arizonica vs. Quercus montana

	Quercus arizonica	Quercus montana
	Arizona oak, Arizona white oak	chestnut oak, mountain chestnut oak, rock chestnut oak
Habit	Trees, evergreen or subevergreen, small to moderate-sized trees, rarely to 18 m. Bark scaly.	Trees, deciduous, to 30 m. Bark dark gray or brown, hard, with deep V-shaped furrows.
Twigs	yellowish, 1.5-2.5 mm diam., persistently felty-tomentose, eventually dingy gray.	light brown, 2-3(-4) mm diam., glabrous.
Buds	dull russet-brown, ovoid, distally subacute or rounded, 3 mm, sparsely pubescent or glabrate.	light brown, ovoid, (3-)4-6 mm, occasionally apex acute, glabrous.
Leaves	blade elliptic or oblong to narrowly obovate or oblanceolate, planar or moderately convex, to (30-)40-80(-90) × 15-30 mm, thick and leathery, usually stiff, base cordate or rounded and weakly cordate, margins entire or coarsely toothed especially near apex, cartilaginously revolute, teeth mucronate-tipped, obscure or prominent, secondary veins ca. 7-11 on each side, branching, passing into teeth when present, apex acute to usually obtuse or broadly rounded; surfaces abaxially dull, sparsely pubescent or subtomentose with curly branched hairs, reticulate from prominent, raised secondary veins, usually glaucous where exposed, adaxially dark or bluish green, moderately lustrous, sparsely and minutely stellate-pubescent, secondary veins slightly raised or prominent within depressions or impressed.	blade obovate to narrowly elliptic or narrowly obovate, (100-)120-200(-220) × 60-100(-120) mm, base subacute or rounded-acuminate, often unequal, margins regularly toothed, teeth rounded or rarely somewhat acute, secondary veins ± parallel, straight or moderately curved, 10-14(-16) on each side, apex broadly acuminate; surfaces abaxially light green, appearing glabrous but with scattered minute, asymmetric, appressed-stellate hairs and usually visible, larger, simple or fascicled erect hairs along veins, adaxially dark green, glossy, glabrous or with minute, scattered, simple hairs.
Acorns	solitary or paired, subsessile, occasionally on peduncle to 15 mm; cup hemispheric or cup-shaped, 5-10(-15) mm deep × 10-15 mm wide, enclosing ca. 1/2 nut, base rounded, margin rather coarse, scales cream to brown, broadly ovate, evenly and strongly tuberculate, tomentose, tips closely appressed; nut light brown, ovoid or oblong, 8-12 mm, nearly glabrous.	1-3, subsessile or on peduncle 8-20(-25) mm; cup shallowly cup-shaped to hemispheric or deeply goblet-shaped, rim thin, often flared and undulate, helmetlike, 9-15 mm deep × 18-25 mm wide, scales often in concentric or transverse rows, laterally connate, gray, broadly ovate, tips reddish, glabrous; nut light brown, ovoid-ellipsoid, 15-30 × 10-20(-25) mm, glabrous.
Cotyledons	connate.	distinct.
2n		= 24.

	Quercus arizonica	Quercus montana
Phenology	Flowering spring.	Flowering mid-late spring.
Habitat	Oak and pinyon woodlands, margins of chaparral, arroyos	Rocky upland forest, dry ridges, mixed deciduous forests on shallow soils
Elevation	1300-2500(-3000) m (4300-8200(-9800) ft)	0-1400 m (0-4600 ft)
Distribution	AZ; NM; TX; Mexico (Chihuahua, Coahuila, Durango, and Sonora) [WildflowerSearch map] [BONAP county map]	AL; CT; DE; GA; IL; IN; KY; MA; MD; ME; MI; MS; NC; NH; NJ; NY; OH; PA; RI; SC; TN; VA; VT; WV [WildflowerSearch map] [BONAP county map]
Discussion	Some of the specimens previously referred to Quercus endemica by C. H. Muller belong here instead. Putative hybrids between Quercus arizonica and Q. grisea (= Q. ×organensis Trelease) are problematic in local areas of contact from southeastern Arizona to western Texas. These intermediates tend to have narrower leaves than Q. arizonica, with moderately reticulate patterns of venation, and more densely hairy leaves. Quercus arizonica and Q. grisea are amply distinct elsewhere, including large areas in northern Mexico, and they appear to be more closely related to other species than to one another (e.g., Q. arizonica with Q. oblongifolia and Q. laeta Liebmann, and Q. grisea with Q. mohriana and Q. microphylla Née). Thus, Q. arizonica and Q. grisea are best treated as distinct species that hybridize, and not as conspecific populations. (Discussion copyrighted by Flora of North America; reprinted with permission.)	The name Quercus prinus Linnaeus is often applied to this species, particularly in the forestry literature, and in many regional floras. In a number of works, however, Q. prinus has been applied to the species here treated as Q. michauxii. Following the recommendations of J. W. Hardin (1979), because of the persistent confusion in the application of the name Q. prinus and uncertainty regarding the identity of the Linnean type materials, the names Q. montana and Q. michauxii should be used for the two species that have been variously called Q. prinus. Quercus prinus under this interpretation is a name of uncertain position. The four species of the chestnut oak group in eastern North America (Quercus montana, Q. michauxii, Q. muhlenbergii, and Q. prinoides) are somewhat difficult to distinguish unless careful attention is paid to features of leaf vestiture and fruit and cup morphology. Attempts to identify these species mostly or solely on basis of leaf shape and dentition (as in many other oak species complexes) have resulted in a plethora of misidentified material in herbaria and erroneous reports in the literature. The closely appressed, asymmetric trichomes on the abaxial surface of the mature leaf, in combination with longer simple hairs along the midvein, are unique to Q. montana among North American species of Quercus. Immature leaves and densely shaded leaves sometimes exhibit a more erect trichome that could be confused with the longer, felty hairs of Q. michauxii, so it is important to evaluate mature sun leaves when possible. (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. 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. 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. 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
Synonyms	Q. sacame
Name authority	Sargent: Gard. & Forest 8: 92. (1895)	Willdenow: Sp. Pl. 4(1): 440. (1805)
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 Web sites: Go Botany, IL Wildflowers, MD Biodiversity, MI Flora WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Quercus montana

Arizona oak, Arizona white oak

chestnut oak, mountain chestnut oak, rock chestnut oak

Habit

Trees, evergreen or subevergreen, small to moderate-sized trees, rarely to 18 m. Bark scaly.

Trees, deciduous, to 30 m. Bark dark gray or brown, hard, with deep V-shaped furrows.

Twigs

yellowish, 1.5-2.5 mm diam., persistently felty-tomentose, eventually dingy gray.

light brown, 2-3(-4) mm diam., glabrous.

Buds

dull russet-brown, ovoid, distally subacute or rounded, 3 mm, sparsely pubescent or glabrate.

light brown, ovoid, (3-)4-6 mm, occasionally apex acute, glabrous.

Leaves

blade elliptic or oblong to narrowly obovate or oblanceolate, planar or moderately convex, to (30-)40-80(-90) × 15-30 mm, thick and leathery, usually stiff, base cordate or rounded and weakly cordate, margins entire or coarsely toothed especially near apex, cartilaginously revolute, teeth mucronate-tipped, obscure or prominent, secondary veins ca. 7-11 on each side, branching, passing into teeth when present, apex acute to usually obtuse or broadly rounded;

surfaces abaxially dull, sparsely pubescent or subtomentose with curly branched hairs, reticulate from prominent, raised secondary veins, usually glaucous where exposed, adaxially dark or bluish green, moderately lustrous, sparsely and minutely stellate-pubescent, secondary veins slightly raised or prominent within depressions or impressed.

blade obovate to narrowly elliptic or narrowly obovate, (100-)120-200(-220) × 60-100(-120) mm, base subacute or rounded-acuminate, often unequal, margins regularly toothed, teeth rounded or rarely somewhat acute, secondary veins ± parallel, straight or moderately curved, 10-14(-16) on each side, apex broadly acuminate;

surfaces abaxially light green, appearing glabrous but with scattered minute, asymmetric, appressed-stellate hairs and usually visible, larger, simple or fascicled erect hairs along veins, adaxially dark green, glossy, glabrous or with minute, scattered, simple hairs.

Acorns

solitary or paired, subsessile, occasionally on peduncle to 15 mm;

cup hemispheric or cup-shaped, 5-10(-15) mm deep × 10-15 mm wide, enclosing ca. 1/2 nut, base rounded, margin rather coarse, scales cream to brown, broadly ovate, evenly and strongly tuberculate, tomentose, tips closely appressed;

nut light brown, ovoid or oblong, 8-12 mm, nearly glabrous.

1-3, subsessile or on peduncle 8-20(-25) mm;

cup shallowly cup-shaped to hemispheric or deeply goblet-shaped, rim thin, often flared and undulate, helmetlike, 9-15 mm deep × 18-25 mm wide, scales often in concentric or transverse rows, laterally connate, gray, broadly ovate, tips reddish, glabrous;

nut light brown, ovoid-ellipsoid, 15-30 × 10-20(-25) mm, glabrous.

Cotyledons

connate.

distinct.

= 24.

Quercus arizonica

Quercus montana

Phenology

Flowering spring.

Flowering mid-late spring.

Habitat

Oak and pinyon woodlands, margins of chaparral, arroyos

Rocky upland forest, dry ridges, mixed deciduous forests on shallow soils

Elevation

1300-2500(-3000) m (4300-8200(-9800) ft)

0-1400 m (0-4600 ft)

Distribution

AZ; NM; TX; Mexico (Chihuahua, Coahuila, Durango, and Sonora)

[WildflowerSearch map]

[BONAP county map]

AL; CT; DE; GA; IL; IN; KY; MA; MD; ME; MI; MS; NC; NH; NJ; NY; OH; PA; RI; SC; TN; VA; VT; WV

[WildflowerSearch map]

[BONAP county map]

Discussion

Some of the specimens previously referred to Quercus endemica by C. H. Muller belong here instead.

Putative hybrids between Quercus arizonica and Q. grisea (= Q. ×organensis Trelease) are problematic in local areas of contact from southeastern Arizona to western Texas. These intermediates tend to have narrower leaves than Q. arizonica, with moderately reticulate patterns of venation, and more densely hairy leaves. Quercus arizonica and Q. grisea are amply distinct elsewhere, including large areas in northern Mexico, and they appear to be more closely related to other species than to one another (e.g., Q. arizonica with Q. oblongifolia and Q. laeta Liebmann, and Q. grisea with Q. mohriana and Q. microphylla Née). Thus, Q. arizonica and Q. grisea are best treated as distinct species that hybridize, and not as conspecific populations.

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

The name Quercus prinus Linnaeus is often applied to this species, particularly in the forestry literature, and in many regional floras. In a number of works, however, Q. prinus has been applied to the species here treated as Q. michauxii. Following the recommendations of J. W. Hardin (1979), because of the persistent confusion in the application of the name Q. prinus and uncertainty regarding the identity of the Linnean type materials, the names Q. montana and Q. michauxii should be used for the two species that have been variously called Q. prinus. Quercus prinus under this interpretation is a name of uncertain position.

The four species of the chestnut oak group in eastern North America (Quercus montana, Q. michauxii, Q. muhlenbergii, and Q. prinoides) are somewhat difficult to distinguish unless careful attention is paid to features of leaf vestiture and fruit and cup morphology. Attempts to identify these species mostly or solely on basis of leaf shape and dentition (as in many other oak species complexes) have resulted in a plethora of misidentified material in herbaria and erroneous reports in the literature. The closely appressed, asymmetric trichomes on the abaxial surface of the mature leaf, in combination with longer simple hairs along the midvein, are unique to Q. montana among North American species of Quercus. Immature leaves and densely shaded leaves sometimes exhibit a more erect trichome that could be confused with the longer, felty hairs of Q. michauxii, so it is important to evaluate mature sun leaves when possible.

(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. 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. 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. 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

Synonyms

Q. sacame

Name authority

Sargent: Gard. & Forest 8: 92. (1895)

Willdenow: Sp. Pl. 4(1): 440. (1805)

Web links

Local Web sites: Go Botany, IL Wildflowers, MD Biodiversity, MI Flora
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

The species comparison tool is brought to you by:

Flora of North America species comparison

Quercus arizonica

Quercus montana

Quercus arizonica

Quercus montana