FNA: Quercus arizonica vs. Quercus shumardii

	Quercus arizonica	Quercus shumardii
	Arizona oak, Arizona white oak	schneck oak, Shumard oak, Shumard red oak, Shumard's oak, swamp red oak
Habit	Trees, evergreen or subevergreen, small to moderate-sized trees, rarely to 18 m. Bark scaly.	Trees, deciduous, to 35 m. Bark gray-brown to dark brown, shallowly fissured with scaly or light-colored flat ridges, inner bark pinkish.
Twigs	yellowish, 1.5-2.5 mm diam., persistently felty-tomentose, eventually dingy gray.	gray to light brown, (1.5-)2-3.5(-4.5) mm diam., glabrous.
Buds	dull russet-brown, ovoid, distally subacute or rounded, 3 mm, sparsely pubescent or glabrate.
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 broadly elliptic to obovate, 100-200 × 60-150 mm, base obtuse to truncate, occasionally acute, margins with 5-9 lobes and 15-50 awns, lobes oblong or distally expanded, apex acute; surfaces abaxially glabrous except for prominent axillary tufts of tomentum, adaxially glossy, glabrous, secondary veins raised on both surfaces.
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.	biennial; cup saucer-shaped to cup-shaped, 7-12 mm high × 15-30 mm wide, covering 1/4-1/3 nut, outer surface glabrous or puberulent, inner surface light-brown to red-brown, glabrous or with ring of pubescence around scar, scales often with pale margins, tips tightly appressed, obtuse or acute; nut ovoid to oblong, occasionally subglobose, 14-30 × 10-20 mm, glabrous, scar diam. 6.5-12 mm.
Cotyledons	connate.
Terminal		buds gray to grayish brown, ovoid or broadly ellipsoid, 4-8 mm, often noticeably 5-angled in cross section, glabrous.

	Quercus arizonica	Quercus shumardii
Phenology	Flowering spring.	Flowering spring.
Habitat	Oak and pinyon woodlands, margins of chaparral, arroyos	Mesic slopes and bottoms, stream banks and poorly drained uplands
Elevation	1300-2500(-3000) m (4300-8200(-9800) ft)	0-500 m (0-1600 ft)
Distribution	AZ; NM; TX; Mexico (Chihuahua, Coahuila, Durango, and Sonora) [WildflowerSearch map] [BONAP county map]	AL; AR; FL; GA; IL; IN; KS; KY; LA; MD; MI; MO; MS; NC; NE; OH; OK; PA; SC; TN; TX; VA; WV; ON [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.)	Trees with shallow cups covering ca. one-fourth of the nut are treated as Quercus shumardii var. shumardii; those with more deeply rounded cups covering ca. one-third of the nut are treated as Q. shumardii var. schneckii (Britton) Sargent. Quercus shumardii var. stenocarpa Laughlin was described from several trees in Missouri and Illinois having ellipsoid acorns that were covered less than one-third their length by very small (5.5-7 mm high × 12.5-18 mm wide), shallow cups (K. Laughlin 1969). Quercus shumardii reportedly hybridizes with Q. buckleyi, Q. falcata (= Q. ×joori Trelease), Q. hemisphaerica, Q. imbricaria (= Q. ×egglestoni Trelease), Q. laevis, Q. laurifolia, Q. marilandica, Q. nigra, Q. palustris (= Q. ×mutabilis E. J. Palmer & Steyermark), Q. phellos (= Q. ×moultonensis Ashe), Q. rubra, and Q. velutina (= Q. × discreta Laughlin). (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. Lobatae
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. 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. 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	Q. schneckii
Name authority	Sargent: Gard. & Forest 8: 92. (1895)	Buckley: Proc. Acad. Nat. Sci. Philadelphia 12: 444. (1860)
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: IL Wildflowers, KS Wildflowers, LA Plants, MD Biodiversity, MI Flora, MO Plants WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Quercus shumardii

Arizona oak, Arizona white oak

schneck oak, Shumard oak, Shumard red oak, Shumard's oak, swamp red oak

Habit

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

Trees, deciduous, to 35 m. Bark gray-brown to dark brown, shallowly fissured with scaly or light-colored flat ridges, inner bark pinkish.

Twigs

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

gray to light brown, (1.5-)2-3.5(-4.5) mm diam., glabrous.

Buds

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

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 broadly elliptic to obovate, 100-200 × 60-150 mm, base obtuse to truncate, occasionally acute, margins with 5-9 lobes and 15-50 awns, lobes oblong or distally expanded, apex acute;

surfaces abaxially glabrous except for prominent axillary tufts of tomentum, adaxially glossy, glabrous, secondary veins raised on both surfaces.

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.

biennial;

cup saucer-shaped to cup-shaped, 7-12 mm high × 15-30 mm wide, covering 1/4-1/3 nut, outer surface glabrous or puberulent, inner surface light-brown to red-brown, glabrous or with ring of pubescence around scar, scales often with pale margins, tips tightly appressed, obtuse or acute;

nut ovoid to oblong, occasionally subglobose, 14-30 × 10-20 mm, glabrous, scar diam. 6.5-12 mm.

Cotyledons

connate.

Terminal

buds gray to grayish brown, ovoid or broadly ellipsoid, 4-8 mm, often noticeably 5-angled in cross section, glabrous.

Quercus arizonica

Quercus shumardii

Phenology

Flowering spring.

Habitat

Oak and pinyon woodlands, margins of chaparral, arroyos

Mesic slopes and bottoms, stream banks and poorly drained uplands

Elevation

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

0-500 m (0-1600 ft)

Distribution

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

[WildflowerSearch map]

[BONAP county map]

AL; AR; FL; GA; IL; IN; KS; KY; LA; MD; MI; MO; MS; NC; NE; OH; OK; PA; SC; TN; TX; VA; WV; ON

[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.)

Trees with shallow cups covering ca. one-fourth of the nut are treated as Quercus shumardii var. shumardii; those with more deeply rounded cups covering ca. one-third of the nut are treated as Q. shumardii var. schneckii (Britton) Sargent. Quercus shumardii var. stenocarpa Laughlin was described from several trees in Missouri and Illinois having ellipsoid acorns that were covered less than one-third their length by very small (5.5-7 mm high × 12.5-18 mm wide), shallow cups (K. Laughlin 1969).

Quercus shumardii reportedly hybridizes with Q. buckleyi, Q. falcata (= Q. ×joori Trelease), Q. hemisphaerica, Q. imbricaria (= Q. ×egglestoni Trelease), Q. laevis, Q. laurifolia, Q. marilandica, Q. nigra, Q. palustris (= Q. ×mutabilis E. J. Palmer & Steyermark), Q. phellos (= Q. ×moultonensis Ashe), Q. rubra, and Q. velutina (= Q. × discreta Laughlin).

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

Source

FNA vol. 3.

Parent taxa

Fagaceae > Quercus > sect. Quercus

Fagaceae > Quercus > sect. Lobatae

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. 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. 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

Q. schneckii

Name authority

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

Buckley: Proc. Acad. Nat. Sci. Philadelphia 12: 444. (1860)

Web links

Local Web sites: IL Wildflowers, KS Wildflowers, LA Plants, MD Biodiversity, MI Flora, MO Plants
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 shumardii

Quercus arizonica

Quercus shumardii