FNA: Quercus dumosa vs. Quercus geminata

	Quercus dumosa	Quercus geminata
	coastal sage scrub oak, Nuttall's scrub oak, scrub oak	sand live oak
Habit	Shrubs, subevergreen, 1-2(-2.5) m, dense, divaricately branching, leaves brittle, often falling when branches disturbed.	Trees, sometimes shrubs, subevergreen, trees to 25 m, shrubs sometimes rhizomatous (if spreading rhizomatously, without numerous straight, short, erect stems emerging from gound, or if so, mixed with other larger branches, infertile, and without dimorphic or asymmetric leaf form).
Bark	smooth when young, eventually scaly.	dark brown or black, scaly.
Twigs	reddish or grayish, 1-1.5(-2) mm diam., glabrous or sparsely stellate-pubescent, soon glabrate.	yellowish, becoming light gray, 1.5-3 mm diam., tomentulose, glabrate in 2d year.
Buds	reddish brown, globose or ovoid, 1-2 mm, glabrous, rarely puberulent near apex.	reddish or dark brown, globose or ovoid, 1-2.5(-3) mm; scale margins glabrous or puberulent.
Leaves	blade undulate or strongly to moderately cupped, occasionally subplanar, 10-20(-25) × 6-15(-20) mm, base cordate or angular-cordate, margins irregularly spinose-toothed or shallowly lobed, rarely entire, often somewhat revolute, secondary veins 3-5(-6) on each side, irregularly branched, apex rounded or spinose-acute; surfaces abaxially sparsely to densely covered with erect, curly, (2-)4(-6)-rayed fasciculate hairs to 0.5 mm, felty to touch in young leaves, adaxially glossy green, glabrate or with scattered stellate hairs, secondary veins somewhat impressed, puberulent.	blade narrowly lanceolate or elliptic, rarely orbiculate, convex-cupped, (10-)35-60(-120) × (7-)10-30(-45) mm, base narrowly cuneate, rarely truncate or rounded, margins strongly revolute, entire, secondary veins 8-10(-12) on each side, apex acute, sometimes obtuse; surfaces abaxially whitish or glaucous, densely covered with minute, appressed, fused-stellate hairs (visible under magnification), and with additional scattered, erect, felty or spreading hairs (sometimes deciduous), or light green and glabrate in shade leaves, adaxially dark or light green, glossy, glabrous or with minute, scattered, stellate hairs, secondary veins moderately to deeply impressed.
Acorns	solitary or paired, subsessile; cup reddish, deeply cup-shaped, 5-8 mm deep × 8-15 mm wide, enclosing 1/3 nut or less, scales long-acute, moderately or scarcely tuberculate at base; nut fusiform or subcylindric, 10-20(-30) × 5-10(-12) mm, apex acute.	1-3, on peduncle 10-100 mm; cup hemispheric or deeply goblet-shaped, sometimes saucer-shaped, 8-15 mm deep × 5-15 mm wide, base often constricted, scales whitish or grayish, thickened basally, keeled, acute-attenuate, tomentulose, tips reddish, glabrous or puberulent; nut dark brown, ovoid, barrel-shaped, or acute, (13-)15-20(-25) × (8-)9-12(-15) mm, glabrous.
Cotyledons	distinct.	connate.

	Quercus dumosa	Quercus geminata
Phenology	Flowering spring.	Flowering spring.
Habitat	Open chaparral, coastal sage scrub	Coastal plain, open evergreen woodlands and scrublands on deep sandy soils, often with pines
Elevation	0-300 m (0-1000 ft)	0-200 m (0-700 ft)
Distribution	CA; Mexico (Baja California) [WildflowerSearch map] [BONAP county map]	AL; FL; GA; LA; MS; NC; SC [WildflowerSearch map] [BONAP county map]
Discussion	Of conservation concern. The name Quercus dumosa has been applied to virtually all scrub oaks in the white oak group of central and southern California and adjacent Baja California. Through the years, and following independent studies by various authors, the concept of this species has gradually narrowed from the original, which included plants here segregated as Q. turbinella, Q. john-tuckeri, Q. cornelius-mulleri, Q. berberidifolia, and Q. pacifica. In degree and constancy, the differences among these species are similar to those separating other commonly recognized tree species of the western United States. The majority of populations referred to Q. dumosa in recent treatments are now included in Q. berberidifolia (see treatment). All of the scrub oaks have a striking superficial similarity because of their shrubby habit and small, often spiny leaves; they differ dramatically in leaf and twig vestiture and acorn form. The concept of Q. dumosa presented here limits it to populations of scraggly shrubs with short petioles, cordate leaf bases, erect curly trichomes on the abaxial leaf surface, and narrow acute acorns that occur at low elevations almost always within sight of the ocean. Because these locations are typically prime real estate, the species, which probably never was common, is highly at risk. It rarely comes into contact with other white oaks because of its low elevation and dry habitat preference; putative hybrids are known, however, with Q. engelmannii and Q. lobata. Some populations of Q. berberidifolia from higher elevations near populations of Q. dumosa show signs of introgression. Named hybrids include Quercus ×kinselae (C. H. Muller) Nixon & C. H. Muller (= Q. dumosa Nuttall × Q. lobata Née) and Q. dumosa Nuttall var. kinselae C. H. Muller (= Q. dumosa × Q. engelmannii). The Luisenos used gall nuts from Quercus dumosa medicinally for sores and wounds and as an astringent (D. E. Moerman 1986). (Discussion copyrighted by Flora of North America; reprinted with permission.)	Quercus geminata occurs in Cuba as putative hybrids. Although some recent authors prefer to treat Quercus geminata as a variety of Q. virginiana, the two species are easily separable and rarely intergrade through most of the broad range in which they are sympatric. Apparently this is primarily because of habitat separation, but additionally Q. geminata flowers much later than Q. virginiana in any given geographic area. At the northern extreme of the range of Q. geminata, apparent intermediates with Q. virginiana are more common, possibly because flowering times of the two species overlap to a greater extent because of slower warming in the spring. Scattered intermediates also occur where the two species are sympatric on sands in coastal Mississippi. (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. 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. 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
Synonyms		Q. virginiana var. geminata
Name authority	Nuttall: N. Amer. Sylv. 1: 7. (1842)	Small: Bull. Torrey Bot. Club 24: 438. (1897)
Web links	Local floras: CA Local Web sites: CalFlora, CalPhotos 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: LA Plants WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Quercus geminata

coastal sage scrub oak, Nuttall's scrub oak, scrub oak

sand live oak

Habit

Shrubs, subevergreen, 1-2(-2.5) m, dense, divaricately branching, leaves brittle, often falling when branches disturbed.

Trees, sometimes shrubs, subevergreen, trees to 25 m, shrubs sometimes rhizomatous (if spreading rhizomatously, without numerous straight, short, erect stems emerging from gound, or if so, mixed with other larger branches, infertile, and without dimorphic or asymmetric leaf form).

Bark

smooth when young, eventually scaly.

dark brown or black, scaly.

Twigs

reddish or grayish, 1-1.5(-2) mm diam., glabrous or sparsely stellate-pubescent, soon glabrate.

yellowish, becoming light gray, 1.5-3 mm diam., tomentulose, glabrate in 2d year.

Buds

reddish brown, globose or ovoid, 1-2 mm, glabrous, rarely puberulent near apex.

reddish or dark brown, globose or ovoid, 1-2.5(-3) mm;

scale margins glabrous or puberulent.

Leaves

blade undulate or strongly to moderately cupped, occasionally subplanar, 10-20(-25) × 6-15(-20) mm, base cordate or angular-cordate, margins irregularly spinose-toothed or shallowly lobed, rarely entire, often somewhat revolute, secondary veins 3-5(-6) on each side, irregularly branched, apex rounded or spinose-acute;

surfaces abaxially sparsely to densely covered with erect, curly, (2-)4(-6)-rayed fasciculate hairs to 0.5 mm, felty to touch in young leaves, adaxially glossy green, glabrate or with scattered stellate hairs, secondary veins somewhat impressed, puberulent.

blade narrowly lanceolate or elliptic, rarely orbiculate, convex-cupped, (10-)35-60(-120) × (7-)10-30(-45) mm, base narrowly cuneate, rarely truncate or rounded, margins strongly revolute, entire, secondary veins 8-10(-12) on each side, apex acute, sometimes obtuse;

surfaces abaxially whitish or glaucous, densely covered with minute, appressed, fused-stellate hairs (visible under magnification), and with additional scattered, erect, felty or spreading hairs (sometimes deciduous), or light green and glabrate in shade leaves, adaxially dark or light green, glossy, glabrous or with minute, scattered, stellate hairs, secondary veins moderately to deeply impressed.

Acorns

solitary or paired, subsessile;

cup reddish, deeply cup-shaped, 5-8 mm deep × 8-15 mm wide, enclosing 1/3 nut or less, scales long-acute, moderately or scarcely tuberculate at base;

nut fusiform or subcylindric, 10-20(-30) × 5-10(-12) mm, apex acute.

1-3, on peduncle 10-100 mm;

cup hemispheric or deeply goblet-shaped, sometimes saucer-shaped, 8-15 mm deep × 5-15 mm wide, base often constricted, scales whitish or grayish, thickened basally, keeled, acute-attenuate, tomentulose, tips reddish, glabrous or puberulent;

nut dark brown, ovoid, barrel-shaped, or acute, (13-)15-20(-25) × (8-)9-12(-15) mm, glabrous.

Cotyledons

distinct.

connate.

Quercus dumosa

Quercus geminata

Phenology

Flowering spring.

Habitat

Open chaparral, coastal sage scrub

Coastal plain, open evergreen woodlands and scrublands on deep sandy soils, often with pines

Elevation

0-300 m (0-1000 ft)

0-200 m (0-700 ft)

Distribution

CA; Mexico (Baja California)

[WildflowerSearch map]

[BONAP county map]

AL; FL; GA; LA; MS; NC; SC

[WildflowerSearch map]

[BONAP county map]

Discussion

Of conservation concern.

The name Quercus dumosa has been applied to virtually all scrub oaks in the white oak group of central and southern California and adjacent Baja California. Through the years, and following independent studies by various authors, the concept of this species has gradually narrowed from the original, which included plants here segregated as Q. turbinella, Q. john-tuckeri, Q. cornelius-mulleri, Q. berberidifolia, and Q. pacifica. In degree and constancy, the differences among these species are similar to those separating other commonly recognized tree species of the western United States. The majority of populations referred to Q. dumosa in recent treatments are now included in Q. berberidifolia (see treatment). All of the scrub oaks have a striking superficial similarity because of their shrubby habit and small, often spiny leaves; they differ dramatically in leaf and twig vestiture and acorn form. The concept of Q. dumosa presented here limits it to populations of scraggly shrubs with short petioles, cordate leaf bases, erect curly trichomes on the abaxial leaf surface, and narrow acute acorns that occur at low elevations almost always within sight of the ocean. Because these locations are typically prime real estate, the species, which probably never was common, is highly at risk. It rarely comes into contact with other white oaks because of its low elevation and dry habitat preference; putative hybrids are known, however, with Q. engelmannii and Q. lobata. Some populations of Q. berberidifolia from higher elevations near populations of Q. dumosa show signs of introgression.

Named hybrids include Quercus ×kinselae (C. H. Muller) Nixon & C. H. Muller (= Q. dumosa Nuttall × Q. lobata Née) and Q. dumosa Nuttall var. kinselae C. H. Muller (= Q. dumosa × Q. engelmannii).

The Luisenos used gall nuts from Quercus dumosa medicinally for sores and wounds and as an astringent (D. E. Moerman 1986).

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

Quercus geminata occurs in Cuba as putative hybrids.

Although some recent authors prefer to treat Quercus geminata as a variety of Q. virginiana, the two species are easily separable and rarely intergrade through most of the broad range in which they are sympatric. Apparently this is primarily because of habitat separation, but additionally Q. geminata flowers much later than Q. virginiana in any given geographic area. At the northern extreme of the range of Q. geminata, apparent intermediates with Q. virginiana are more common, possibly because flowering times of the two species overlap to a greater extent because of slower warming in the spring. Scattered intermediates also occur where the two species are sympatric on sands in coastal Mississippi.

(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. 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. 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

Synonyms

Q. virginiana var. geminata

Name authority

Nuttall: N. Amer. Sylv. 1: 7. (1842)

Small: Bull. Torrey Bot. Club 24: 438. (1897)

Web links

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).

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Quercus dumosa

Quercus geminata

Quercus dumosa

Quercus geminata