Title: Identifying Hardwoods Growing on Pine Sites
Forest Service General Technical Report SO-15
Clair A. Brown
Harold E. Grelen
Southern Forest Experiment Station
U.S. Department of Agriculture,
Forest Service
General Technical Report SO-15
The authors thank Bryan A. Jowers, Glendale, California, for the excellent winter silhouettes. For help in obtaining specimens or photographs of species not easily accessible to us, we thank the following: Roger W. Barbour, University of Kentucky; William Harlow, College of Environmental Science and Forestry, State University of New York; Richard Johnson, Caroline Dormon Nature Preserve; Betty E. Lemon, University of Southwestern Louisiana; R. Dale Thomas, Northeast Louisiana University; and Lino Della-Bianca and Edwin R. Lawson of the U.S. Forest Service.
This publication illustrates and describes 26 hardwood species or varieties, including 16 oaks and hickories, with photographs of leaves, bark, buds, flowers, and fruits. Line drawings feature the winter silhouette of each species and a key is included to assist in identification.
US. Department of Agriculture
Forest Service General Technical Report SO-15
CLAIR A. BROWN
Professor Emeritus,
Department of Botany
Louisiana State University
Baton Rouge, Louisiana
HAROLD E. GRELEN
Principal Range Scientist
Southern Forest Experiment Station
Forest Service—USDA
Pineville, Louisiana
1977
For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402
Throughout the South some 49 billion cubic feet of small, low-quality hardwoods are growing on southern pine sites[1] (Staff, For. Resour. Res. Work Unit 1976). This material is usually wasted; if the site is prepared for regeneration to pine, the hardwoods there are destroyed. Research is underway to find economical methods of harvesting and utilizing these hardwoods. The descriptions, key, and illustrations in this book should help wood utilization researchers, especially those new to the South, to identify the most prevalent hardwood species on southern pine sites (Table 1).
Percentages were derived from Staff, For. Resour. Res. Work Unit (1976).
Nomenclature used herein follows Little (1953).
| Species | Percent | ||
|---|---|---|---|
| Sweetgum | Liquidambar styraciflua L. | 13.2 | |
| White oak | Quercus alba L. | 12.3 | |
| Hickory | Carya spp. | 8.5 | |
| Southern red oak | Quercus falcata Michx. | 8.1 | |
| Post oak | Quercus stellata Wangenh. | 7.0 | |
| Yellow-poplar | Liriodendron tulipifera L. | 7.0 | |
| Black tupelo | Nyssa sylvatica Marsh. | 5.5 | |
| Water oak | Quercus nigra L. | 4.7 | |
| Black oak | Quercus velutina Lam. | 4.0 | |
| Scarlet oak | Quercus coccinea Muenchh. | 3.6 | |
| Red maple | Acer rubrum L. | 3.6 | |
| Chestnut oak | Quercus prinus L. | 2.9 | |
| Northern red oak | Quercus rubra L. | 2.4 | |
| Laurel oak | Quercus laurifolia Michx. | 1.4 | |
| Elm | Ulmus spp. | 1.4 | |
| Cherrybark oak | Quercus falcata var. pagodaefolia Ell. | 1.2 | |
| Ash | Fraxinus spp. | .9 | |
| Sweetbay | Magnolia virginiana L. | .6 | |
| Shumard oak | Quercus shumardii Buckl. | .2 | |
| Hackberry | Celtis spp. | .1 | |
| Other hardwoods | including blackjack oak (Quercus marilandica Muenchh.) | 11.4 | |
| Total hardwoods | 100.0 | ||
Hickories have alternate compound leaves with 5 to 13 leaflets. They are monoecious; that is, the stamens and pistil are borne in separate flowers on the same plant. Flowers generally develop after the leaves are three-fourths to full grown. Staminate flowers are in catkins, which occur on last year’s wood and usually have three branches. The stalkless pistillate flowers are in several-flowered spikes at the apex of the current season’s growth. Catkins last from 10 days to 3 weeks and are usually not useful in distinguishing the species. The fruit, however, is widely used for identification. The husk may be very thin (about 1 mm), moderately thick (3 to 5 mm), or very thick (more than 5 mm). Similarly, the shell may be thin, moderately thick, or very thick. The meat varies from sweet to bitter. Upon drying, the husk usually separates along sutures and frees the nut. In some species the husk partly splits at the sutures but still encloses the nut when it falls. Such nuts are usually sterile, because the meat is seldom filled out.
For identification purposes use nuts from the ground with caution; if more than one species grows in the vicinity, the fruits could be mixed. Also some trees shed defective or sterile fruits early, and these fruits are often different in shape and size from typical fruit.
Hickories are generally divided into true hickories, which have overlapping (imbricate) bud scales, and pecan hickories, which have valvate bud scales. True hickories are divided into those with tight bark and those with loose bark. Mockernut Hickory, Carya tomentosa Nutt., a tight bark species, has very pubescent leaves, large buds, and a thick husk over a large nut. Pignut Hickory, C. glabra (Mill.) Sweet, also a tight bark hickory, has three to nine glabrous leaflets and a tardily dehiscing husk about 3 mm thick. Shagbark Hickory, C. ovata (Mill.) K. Koch, is one of the few species with bark in thin, loose plates. It has small buds and usually has five leaflets. Bitternut Hickory, C. cordiformis (Wangenh.) K. Koch, belongs to the pecan hickory group and has yellow buds with valvate scales. It also has tight bark, thin four-winged husks, thin shells, and bitter meat.
Oaks are also monoecious, and staminate flowers are in drooping catkins, which consist of a central, flexible axis with sessile, apetalous and pubescent flowers. They are most abundant on the developing new twigs. Although catkins vary among oaks, they are usually not used as distinguishing characteristics because they last only 2 to 3 weeks. Pistillate flowers occur on wood of the previous season and in leaf axils of twigs. In red oaks, however, pistillate flowers on current twigs do not mature until the second fall.
The fruit, a nut or acorn, consists of the seed enclosed in a shell. The nut is seated in a cup consisting of many scales. At maturity nuts are shed from the tree by shrinkage of the cup (dehydration). Considerable variation in mature acorn size occurs among trees of a species, notably in water oak, willow oak, and white oak.
Differences in foliage within a species also complicate identification. 3 Apparently because lower leaves receive less sunlight they differ in size and appearance from those in the middle or upper crown. Most taxonomists prefer a specimen from the upper half of the crown because they consider leaves from this area typical for the species. To get such specimens easily, use a tree pruner and take leaves from at least 20 to 30 feet off the ground or collect them from freshly felled trees. Moreover, foliage of seedlings and small saplings often differs from that of mature trees, and spring and summer growth flushes on the same branch often appear markedly different. This seasonal variation has been noted for many oaks, including laurel, post, blackjack, and especially water oak. For example, by late March or April, water oak leaves reach their normal size and shape—obovate with a wavy apex; the second flush of growth, which starts in late April or May, produces lobed leaves.
Identification is further complicated because hybrids commonly occur among the oaks.
The oaks are divided into two main groups: the white oaks and the red (or black) oaks. The white oaks have leaves with rounded lobes and no bristles; acorns mature the first fall, and the inner surface of the shell is glabrous. White oak, chestnut oak, and post oak belong to this group. The red oak group is characterized by bristle-tipped leaf lobes in such species as Shumard, southern red, northern red, cherrybark, and black oak. The red oak group also includes non-lobed species such as water, laurel, and willow oak, which usually have entire margins. Blackjack oak leaves usually lack lobes and bristles, but leaves with terminal lobes occasionally occur and may have one bristle per lobe. Acorns mature the second fall, and the inner surface of the shell is pubescent.
Southern Red Oak, Quercus falcata Michx., and its variety Cherrybark Oak, Q. falcata var. pagodaefolia Ell., have almost identical acorns, but they can be distinguished by other characteristics. The leaf base of southern red oak is somewhat bell-shaped, but that of cherrybark is not. Southern red oak forms heavy ridges of bark; cherrybark does not.
The distinctive feature of Black Oak, Q. velutina Lam., is its yellow-orange inner bark. Its leaves take three forms. Seedlings to small saplings have a “bear-paw” leaf with only a suggestion of lobing. Lower leaves on large trees also have little lobing, but leaves from the middle and upper crown are clearly lobed. The uppermost leaves, which have seven lobes and deep sinuses, are usually illustrated as typical.
Scarlet, Q. coccinea Muenchh., Northern Red, Q. rubra L., and Shumard Oak, Q. shumardii Buckl., are difficult to distinguish. Northern red oak leaves have shallow sinuses and a dull-green upper surface with little or no pubescence in the vein axils on the underside. Shumard oak leaves have a glossier surface, shallow to deep sinuses that are usually wider than the adjacent lobes, and definite hairiness at the vein axils. The sinuses of scarlet oak are also usually wider than their adjacent lobes, which are usually toothed. Both Shumard and scarlet oak have outstanding fall coloration.
Blackjack Oak, Q. marilandica Muenchh., can be recognized by its leathery, usually entire, broadly obovate leaf, which has a rusty undersurface. The branches are stout, irregular, gnarled, drooping to horizontal.
Laurel Oak, Q. laurifolia Michx., and Water Oak, Q. nigra L., are similar in size and shape, but water oak has oblong-obovate or spatula-shaped leaves gradually narrowed to a wedge-shaped base. Laurel oak leaves are elliptic to oblong-ovate. Laurel oaks tend to shed leaves late and thus may retain about 30 to 50 percent of their lower leaves after water oaks are bare. Some recent authors separate the laurel oaks into two species, upland laurel oak, Q. hemisphaerica Bartr., and swamp laurel oak, Q. laurifolia Michx.
White Oak, Q. alba L., has a thin, light green leaf with a light glaucous bloom at maturity; it is oblong or ovate, with rounded lobes and three to five narrow sinuses extending nearly to the mid-rib. The cup scales of the acorn-cup are heavy and distinct.
Post Oak, Q. stellata Wangenh., has stout, irregular branches. The leathery leaves are usually five-lobed; usually the two side lobes are at right angles to the central axis, thus forming a cross-shaped leaf.
Chestnut Oak, Q. prinus L., resembles swamp chestnut oak, Q. michauxii Nutt., a commercially important tree southwide. Chestnut oak is primarily a northeastern tree, extending into the South along the Appalachian highlands into northern Georgia and Alabama where its range overlaps that of swamp chestnut oak, and its leaves lack the dense pubescence found on those of swamp chestnut oak.
Common elms include American Elm, Ulmus americana L., and Winged Elm, U. alata Michx. Both bloom after a freeze breaks dormancy. For example, if a killing frost occurs in the last week of November or the first week of December, American elm will bloom the first week of January. If no killing frost occurs by early December. American elm may not bloom until the third week of January. Winged elm usually blooms 10 days to 2 weeks later than American elm. Small winged elm trees frequently have a corky outgrowth on opposite sides of twigs at least 3 years old. Mature trees often lack this characteristic. The American elm leaf has unequal basal lobing and pubescent or ciliate samaras about 12 mm in diameter; winged elm has a smaller leaf with round to acute leaf bases and a very ciliate samara about 8 mm long.
Young Sugarberry, Celtis laevigata Willd., and Hackberry, C. occidentalis L., trees are readily recognized by a whitish to light gray bark dotted with small corky warts. Older trees often have relatively smooth, light to medium gray bark. Leaf margins of sugarberry are usually entire or indistinctly toothed; the upper half of hackberry leaves are usually conspicuously serrate. Both species produce tiny flowers on the new growth when the leaves are about half normal size. The fruit of sugarberry is orange-red to black; that of hackberry is dark red to nearly black at maturity.
Yellow-poplar, Liriodendron tulipifera L., or tulip tree, has alternate, four- to six-lobed leaves with truncate to distinctly notched apices, a unique feature among American trees. The flowers are tulip-like with red markings on a greenish-yellow background. The fruit is a cone-like aggregate of samaras.
Sweetbay, Magnolia virginiana L., produces moderate-sized trunks on uplands or numerous pole-like suckers in branch bottoms. It is evergreen in the southern part of its range and deciduous in the northern portion. A wind blowing in the crown will expose the silvery underside of the leaves. The white flowers, about 5 to 10 cm in diameter, open for the first time about 3 p.m. and close about 9 p.m. They reopen the next morning and shed their stamens. The fruit is a green pickle-like aggregate of follicles that splits open to reveal red seeds. Sweetbay and yellow-poplar, both members of the Magnolia family, have stipule scars circling the twigs.
Sweetgum, Liquidambar styraciflua L., or redgum, is easily recognized by its alternate, star-shaped, palmately lobed leaves. Some trees have corky outgrowths on the small branches. Its flower consists of several round clusters of stamens arranged in a raceme and a stalked pistillate head that develops into a spiny, woody fruit containing many seeds.
Red Maple, Acer rubrum L., has simple, opposite leaves that are usually glaucous and pubescent. The flowers appear in early February and the fruit is a double samara. The variety A. rubrum var. drummondii (Hook. and Arn.) Sarg., which has densely matted white hairs on the undersides of young leaves, grows in swamps throughout the South. Leaves may have three to five lobes, but southern trees are predominantly three-lobed. For this reason, some authors recognize the southern form as A. rubrum var. tridens Woods.
The leaves of Black Tupelo (blackgum) Nyssa sylvatica Marsh., are alternate, elliptical to obovate, and become spotted early in their development, turning purplish in September before their early shedding. The flowers are small, inconspicuous, and produce a blue-black fruit.
Two of the most common ashes are White Ash, Fraxinus americana L., and Green Ash, F. pennsylvanica Marsh. The most reliable distinction between the two species appears to be samara differences. White ash has a plump, short seed end with the wing practically terminal, whereas green ash has a slender seed end and the wing extends more than halfway down the seed end. White ash usually has a rounded leaflet base, but green ash has wedge-shaped leaflet bases. The undersurfaces of fresh white ash leaves are white, but the color is difficult to detect on dry specimens. Green ash leaves are green on both surfaces, although somewhat paler on undersurfaces.
The key is composed of paired statements, one true and one false for any given specimen. The guide numbers at the end of statements are used to locate the next pair. Follow the true statements until you come to a common name. If you have made no mistake in interpreting the paired statements, you should arrive at the correct identity of the specimen. Then check the text and illustration.
Bark grayish, tight, marked with distinct diamond-shaped ridges and furrows. Branches stout, drooping to spreading and ascending. Twigs 10 to 12 mm in diameter, conspicuous leaf scars. Buds (terminal) 10 to 15 mm long, 5 to 8 mm in diameter, scales imbricate. Leaves alternate, deciduous, odd-pinnately compound, 20 to 40 cm long with 5 to 7 drooping leaflets; yellow hairs and glandular hairs on lower leaflet surface, apex acuminate, margin finely serrate, base obtuse, on very short petiolules. Flowers unisexual, appearing in spring with developing leaves, staminate in 3-parted drooping catkins, pistillate terminal on new growth. Fruit subglobose to obovate, 3 to 5 cm in diameter, husk 1 cm thick, slow to open, shell of nut thick and hard, meat sweet.
Mockernut Hickory/Carya tomentosa
Bark light to dark gray, often blackish, rough and deeply furrowed. Branches stout, drooping to spreading. Twigs 3 to 5 mm in diameter, reddish brown, smooth. Buds ovoid, acute, glabrous, 8 to 12 mm long, scales imbricate. Leaves alternate, deciduous, odd-pinnately compound, 20 to 40 cm long, usually with 7 leaflets; upper pair and terminal largest, 10 to 15 cm long by 4 to 6 cm wide, broadly oval to slightly obovate. Flowers unisexual, staminate in 3-branched catkins appearing about the time of leaf maturity; pistillate terminal on new growth. Fruit oblong to obovoid to obpyriform, 30 mm in diameter by 35 mm long, husk about 3 mm thick, tardily dehiscent, shell of nut thick, meat sweet.
Pignut Hickory/Carya glabra
Bark smooth at first, then breaking into long, flat, irregular gray strips, to 5 mm thick, usually attached at the apex, free at the base. Branches stout, smooth, spreading to ascending. Twigs stout, orange-brown, leaf scars large. Buds (terminal), 10 to 20 mm long, 6 to 8 mm in diameter, scales imbricate. Leaves alternate, deciduous, odd-pinnately compound with 5 to 7 leaflets, usually 5 to 18 cm wide and 20 to 35 cm long; lateral leaflets ovate to ovate-lanceolate, terminal leaflet usually obovate, apices acute to acuminate, margins finely serrate, bases wedge-shaped, more or less yellow, pubescent below, gradually becoming glabrous with age. Flowers unisexual, appearing in spring with the developing leaves, staminate in 3-lobed catkins, pistillate on new growth. Fruits subglobose, 2.5 to 6 cm in diameter, husk 3 to 5 mm thick, shell of nut hard and moderately thin, meat sweet.
Shagbark Hickory/Carya ovata
Bark brown to slate gray, smooth to lightly furrowed or with strongly interlaced ridges. Branches stiff, ascending, spreading. Twigs slender, glossy, often with yellow glands early in the season. Buds compressed, ovoid, 6 to 10 mm long, covered with yellow, valvate glandular scales. Leaves alternate, deciduous, odd-pinnately compound, 15 to 25 cm long with 7 to 9 leaflets, 7 to 15 cm long and 3 to 6 cm wide; lateral leaflets narrowly to broadly elliptic, terminal leaflet largest and usually obovate, apex acuminate, margin finely serrate, base wedge-shaped, with yellow glands on undersurfaces and on rachis. Flowers unisexual, staminate in 3-branched catkins appearing after leaves; pistillate terminal on new growth. Fruit ovate to subglobose, 2 to 3 cm in diameter, often slightly compressed, 4-winged on sutures from apex to middle of husk, husk thin, covered with yellow glandular scales, shell of nut thin, meat very bitter.
Bitternut Hickory/Carya cordiformis
Bark dark brown to grayish black, divided by shallow, irregular fissures into broad ridges. Branches stout, spreading to ascending. Twigs 2 to 5 mm in diameter, dull reddish brown. Buds ovoid, angulate 8 to 13 mm long, apex acute. Leaves alternate, deciduous, simple, many remaining as dead foliage until spring, ovate to obovate with bell-shaped base, 10 to 28 cm long, 7 to 30 cm wide; with 3 to 9 lobes and margins with deep rounded sinuses; when 3-lobed, central lobe strap-shaped and toothed near the apex and side lobes acute to acuminate, somewhat falcate; permanently pubescent below, white at first, turning rust. Flowers unisexual, staminate in tomentose catkins as leaves unfold; pistillate in leaf axils on twigs. Fruit an acorn, small, spherical to hemispherical; cup 12 to 15 mm wide, shallow saucer-shaped, enclosing about one-fourth to one-half of the nut; nut 8 to 12 mm long.
Southern Red Oak/Quercus falcata
Bark dark gray to gray-black consisting of appressed scales in narrow flat ridges with shallow furrows. Branches stout, spreading to ascending. Twigs 2 to 4 mm in diameter, reddish, lightly fluted. Buds ovoid, 10 to 15 mm long, angled, scales pubescent with dark margins. Leaves alternate, tardily deciduous, persisting into December, simple, oval to oblong, 12 to 20 cm long, 7 to 8 cm wide; with 5 to 11 lobes, major lobes opposite each other, large rounded sinuses extending nearly to the midrib, margin entire with occasional bristle-tipped teeth near the apex of the lobes, dark green above, permanently pubescent below, sometimes thinly so, varying from white to rust color, especially on drying. Flowers as in Q. falcata. Fruit an acorn broader than tall; cups 12 to 15 mm wide; nut about 8 to 10 mm long, subglobose, flattened at base, rounded at apex.
Cherrybark Oak/Quercus falcata var. pagodaefolia
Bark brownish-black on older trees, with thick, broad scaly ridges and deep furrows; inner bark yellow-orange—the only American oak with this feature. Branches stout, spreading to ascending. Twigs about 5 mm in diameter, reddish brown to dark brown, lightly fluted. Buds ovoid, 10 to 15 mm long, lateral buds sharply angled, scales ciliate, margin dark. Leaves alternate, deciduous, simple; membranous in seedlings and saplings to somewhat leathery in the middle to upper crown; lower leaves broadly elliptic to obovate, 15 to 30 cm long, 10 to 15 cm wide, entire to faintly lobed; middle-crown leaves 10 to 20 cm long, 10 to 15 cm wide, distinctly 5 to 9 lobed with broad rounded sinuses with apical bristles on each lobe; upper-crown leaves oblong to obovate, 8 to 20 cm long, 8 to 15 cm wide; dark shiny green above, yellow scurfy pubescence on young leaves of middle and upper crown, petioles 4 to 6 cm long, yellow to reddish. Flowers unisexual; staminate catkins 7 to 15 cm long; pistillate on short tomentose peduncles. Fruit an oval to obovoid acorn 10 to 25 mm long; cup cup-shaped to conical enclosing about one-half of the nut.
Black Oak/Quercus velutina
Bark dark grayish-black, divided into irregular fissures and scaly ridges. Branches stout, spreading to ascending. Twigs 3 to 4 mm in diameter, reddish, turning a dull red. Buds ovoid, acute, 5 to 7 mm long, covered with rounded, lightly pubescent scales. Leaves alternate, deciduous, simple; glabrous, except in axils of main veins on underside, oval to slightly obovate, 8 to 17 cm long, 5 to 13 cm wide, with 5 to 9 deep lobes often terminated by secondary lobes with bristle tips, sinuses usually deep, round, and wider than lobes; both surfaces pale green, upper surface shiny, bright scarlet in autumn, petioles about 4 cm long. Flowers unisexual; staminate in catkins with developing leaves; pistillate on pubescent peduncles. Fruit an acorn; cup 15 to 30 mm wide, covered with brown scales enclosing about one-third to one-half of the nut; nut ovoid, 10 to 20 mm long, occasionally with ring grooves near apical point at maturity.
Scarlet Oak/Quercus coccinea
Bark dark brown, thick, divided by shallow furrows into long, flat-topped scaly ridges. Branches stout, spreading and ascending to form a round-topped crown. Twigs slender, reddish-brown to dark red. Buds ovate, acute, light brown, 8 to 10 mm long. Leaves alternate, deciduous, simple, oblong to oval to obovate, 12 to 22 cm long, 10 to 15 cm wide; 7 to 11 short lobes, lobes 3-toothed, bristle-tipped; upper surface dull green. Flowers unisexual; staminate in slender catkins appearing with the developing leaves, pistillate inconspicuous on last year’s wood. Fruit an acorn, 15 to 30 mm long; cup saucer-shaped, enclosing about one-fourth of the nut.
Northern Red Oak/Quercus rubra
Bark dark gray to blackish, relatively smooth at first, then breaking into scaly ridges. Branches spreading to ascending. Twigs about 5 mm in diameter, olive green then turning dark reddish. Buds clustered at apex 5 to 7 mm long, sharp pointed, strongly angled. Leaves alternate, deciduous, simple; oval to slightly obovate, 10 to 20 cm long, 6 to 15 cm wide; with 7 to 10 bristle-tipped lobes, lobes on upper crown leaves narrower to slightly wider than sinuses, lobes on lower crown leaves wider than sinuses; dark green above, paler below, glabrous except for vein axils on lower surface; petiole about 5 cm long. Flowers unisexual; staminate in yellow catkins appearing with the unfolding leaves; pistillate on pubescent peduncles. Fruit an acorn; cup 20 to 31 mm across, enclosing about one-fourth of the nut; nut about 25 mm long, 15 mm in diameter.
Shumard Oak/Quercus shumardii
Bark black, very rough, consisting of thick blocky plates. Branches stout, spreading to drooping. Twigs stout, about 5 mm in diameter. Buds with rusty brown hairs, about 4 to 8 mm long. Leaves alternate, tardily deciduous, simple, 7 to 25 cm long, broadly obovate at apex (bear-paw shape) tapering to a narrow base, margin entire or with 3 bristle-tipped apical lobes, upper surface dark green, rusty pubescent on undersurfaces. Flowers unisexual; staminate in catkins, appearing with the leaves; pistillate solitary or paired. Fruit an acorn, cup enclosing one-half to two-thirds of the nut; nut nearly ovoid, 20 to 25 mm long by 15 to 20 mm in diameter.
Blackjack Oak/Quercus marilandica
Bark nearly black, divided into broad flat ridges by deep fissures. Twigs 2 to 3 mm in diameter, usually reddish brown. Buds ovoid, reddish brown, 2 to 4 mm long. Leaves alternate, semi-deciduous, simple, a few shed in fall, a few persisting until spring; elliptic to spatulate, 7 to 15 cm long, 2 to 4 cm wide; apex acute or obtuse, margin entire, base cuneate; shiny green above, paler below; petioles 3 to 5 mm long, midrib conspicuous on underside. Flowers unisexual; staminate in catkins as leaves unfold; pistillate on twigs at leaf scars. Fruit an acorn, sessile to subsessile, cup 15 to 20 mm wide, enclosing about one-fourth of nut; nut hemispheric, rounded at apex and flattened at bottom, 15 mm long.
Laurel Oak/Quercus laurifolia
Bark smooth, grayish black, becoming scaly with age. Branches spreading to ascending, forming a round-topped crown in the open. Twigs 3 to 5 mm in diameter, gray. Buds ovoid, acute, reddish brown, 3 to 7 mm long. Leaves alternate, deciduous, simple; variable in shape and size, obovate to spatulate, 5 to 10 cm long, 2 to 5 cm wide; margin entire, wavy to distinctly lobed in juvenile specimens; sessile or with petiole to 1 cm long. Flowers unisexual; staminate catkins 5 to 8 cm long, pistillate catkins short-peduncled. Fruit an acorn about 15 mm wide, 10 mm high; cup thin, enclosing about one-fifth to one-third of the nut.
Water Oak/Quercus nigra
Bark light gray, separated by shallow furrows into flat ridges with loose appressed scales. Branches stout, drooping, spreading to ascending. Twigs 2 to 3 mm in diameter, reddish. Buds globose to ovoid, angulate, apex acute to obtuse, 3 to 5 mm. Leaves alternate, deciduous, simple, oblong to obovate, 7 to 20 cm long, 4 to 10 cm wide, with 7 to 11 uneven, rounded lobes and deep sinuses. Flowers unisexual, in catkins, preceding leaf expansion. Fruit an acorn, 15 to 35 mm long, 20 to 25 mm in diameter, cup 1.5 to 3 cm wide, usually cup-shaped, conspicuous with thickened scales, enclosing one-fourth to one-third of the nut.
White Oak/Quercus alba
Bark medium to dark gray, with deep furrows, scaly ridges. Branches stout, irregular, drooping to horizontal and ascending. Twigs 3 to 5 mm in diameter, gray to brownish. Buds broadly ovate, blunt to acute, 5 mm long, clustered at apex of twig. Leaves alternate, deciduous, simple; obovate, to 18 cm long, 5 to 10 cm wide; divided into 5 to 7 sinuate rounded lobes, the two lower lobes smaller than the upper pair, upper lobes and the terminal lobe resembling a cross, dark, shiny green above, grayish to brownish below, leathery. Flowers unisexual; staminate in catkins appearing with the unfolding leaves; pistillate on last year’s wood. Fruit an acorn, 13 to 25 mm long, 6 to 20 mm in diameter; cup hemispherical, enclosing about one-half of the nut, cup scales rusty-pubescent; nut ovate to ovate-oblong, about 15 mm long.
Post Oak/Quercus stellata
Bark dark reddish brown to nearly black, deeply furrowed with narrow ridges. Branches stout, spreading to ascending. Twigs stout, angulate, smooth, purplish-green when new, turning orange or reddish-brown. Buds ovate-conical, somewhat angulate, 8 to 12 mm long, silky hairy. Leaves alternate, deciduous, simple; elliptic to obovate, 10 to 30 cm long, 3 to 8 cm wide; somewhat leathery, margin crenate with a vein ending in each rounded tooth, smooth green above, stellate-pubescent below. Flowers unisexual; staminate in catkins 5 to 10 cm long; pistillate in short spikes on stout peduncles. Fruit an acorn 25 to 35 mm long, 15 to 25 mm in diameter; cup vase-shaped, thin, rough with thickened scales, covering one-third to one-half of the nut.
Chestnut Oak/Quercus prinus
Bark dark, smooth at first becoming deeply furrowed on larger trees. Branches slender, ascending to spreading, corky ridges or wings on branches 3 years or older. Twigs about 2 mm in diameter, light green tinged with red. Buds sharp-pointed, divergent from twig 3 to 4 mm long. Leaves alternate, deciduous, simple; broadly ovate to elliptic, 4 to 8 cm long, 2 to 4 cm wide; apex acute to short-acuminate, margin doubly to triply serrate, base rounded; dull green above, lighter green below with prominent pinnate veins. Flowers perfect, abundant, tiny, opening just before leaves unfold, several in a cluster at a leaf scar, blooming late January into February. Fruit a samara, flat and elliptic, 6 to 8 mm long, margin ciliate.
Winged Elm/Ulmus alata
Bark gray to blackish, thick, divided into flat ridges by deep furrows. Branches ascending, arching, and spreading; open-grown trees vase-shaped in outline. Twigs 2 to 3 mm in diameter with 5 to 7 leaves which increase in size from basal to apical leaf, red-brown. Buds (leaf) brown, small, scaly, acute. Leaves alternate, deciduous, simple; broadly ovate, 5 to 15 cm long, 4 to 6 cm wide; apex acuminate, margin usually doubly serrate, base oblique on short petiole; upper surface smooth, marked with sunken veins pinnately arranged; veins more prominent on underside. Flowers perfect, buds greatly enlarge before opening; with very small flowers abundant in clusters; opening before the leaves expand, blooming from late December into February. Fruit a samara, oval to circular with wing surrounding the seed, about 10 mm in diameter, margin ciliate.
American Elm/Ulmus americana
Bark light gray to almost white, thin, smooth, usually more or less studded with irregular corky outgrowths. Branches spreading, slender. Twigs about 3 mm in diameter, reddish-brown. Buds about 3 mm long, alternate. Leaves alternate, deciduous, simple; narrowly elliptic to broadly ovate, 6 to 10 cm long, 2 to 4 cm wide; apex acute, margin usually entire, base broadly rounded or oblique. Flowers unisexual or perfect, tiny, inconspicuous, many staminate and few pistillate appearing on the new growth as the leaves unfold. Fruit a drupe with a bony reticulated nutlet, about 5 mm in diameter, orange-red on a pedicel often shorter than the petiole of the subtending leaf.
Sugarberry; hackberry/Celtis laevigata
Bark thin and dark green on young trees, becoming ash-gray and conspicuously furrowed and ridged with age. Branches spreading to ascending, often drooping on large open-grown trees. Twigs smooth, about 5 mm in diameter, encircled by stipule scars, red-brown. Buds (terminal) grayish green, turning red in winter, flat about 10 to 16 mm long, scales valvate. Leaves alternate, deciduous, simple; dark green above, turning yellow in fall; 6 to 20 cm long and as wide as long; petioles 5 to 20 cm long, often longer than the blades on low branches. Flowers perfect, tulip-shaped, about 4 to 6 cm long, greenish-yellow with orange to reddish markings at base of petals, color intensifies with age. Fruit an aggregate cone, 5 to 8 cm long, gradually shattering into one-seeded, winged samaras.
Yellow-poplar/Liriodendron tulipifera
Bark dark gray, usually smooth, thin, in shady areas often encrusted with mosses, liverworts, and lichens. Branches stout, spreading to ascending. Twigs about 5 to 7 mm in diameter, encircled by stipule scars, green. Buds (terminal), silvery gray, pubescent, 15 mm long; smaller lateral buds often subtended by persistent petiole base. Leaves alternate, evergreen in South, deciduous in northern part of range, simple; elliptic to oblong, 10 to 15 cm long, 4 to 6 cm wide; margin entire, dark green above, silvery pubescent below. Flowers perfect, white, sweet-scented, 5 to 8 cm in diameter, appearing May to September. Fruit an aggregate of follicles which open and shed red seeds, irregular in shape, ovoid to ellipsoid, smooth, about 5 cm long.
Sweetbay/Magnolia virginiana
Bark dark gray, divided by deep furrows into narrow, rounded ridges. Branches stout, often with corky wings or outgrowths. Twigs about 4 to 6 mm in diameter, gray-brown. Buds (terminal) broadly egg-shaped, about 10 to 15 mm long, scales overlapping, slightly sticky. Leaves alternate, deciduous, simple; palmately 5- to 7-lobed; 8 to 20 cm wide, 6 to 15 cm long, often longer than broad; margin finely serrate; petioles 4 to 13 cm long. Flowers unisexual (plants monoecious), appearing as the leaves unfold; staminate clustered in terminal racemes; pistillate in small drooping spherical heads. Fruit in stalked spherical heads covered with small spine-like projections; seed cavity at base of each spine.
Sweetgum; redgum/Liquidambar styraciflua
Bark gray, divided into scaly ridges by narrow furrows. Branches slender, spreading and ascending. Twigs about 3 mm in diameter, reddish. Buds spherical, reddish, clustered at apex of twig, scales with white ciliate margins. Leaves opposite, deciduous, simple; ovate to almost circular, 4 to 9 cm long, 2.5 to 7 cm wide, usually longer than broad; 3-lobed near the apex, margin finely serrate; dark green above, glaucous and lightly pubescent below, pubescence usually shed. Flowers typically polygamous, occasionally with perfect flowers, small, forming dense clusters from separate buds before leaf expansion, conspicuous because of the red to orange coloration. Fruit twin samaras 10 to 20 mm long.
Var. drummondii: Leaves larger than typical red maple, usually broader than long; 3 to 5 lobes or occasionally scarcely lobed, margins coarsely toothed, conspicuously glaucous below, usually permanently tomentose. Fruit samaras 4 to 5 cm long.
Red Maple/Acer rubrum
Bark black, marked with furrows and cross-cracks that divide the ridges into squarish plates. Branches slender, spreading to horizontal, often drooping in open-grown specimens. Twigs 2 to 3 mm in diameter, gray to reddish. Buds obtuse, of overlapping yellow-brown scales, terminal buds 6 mm long. Leaves alternate, early deciduous, simple; marked with irregular black spots and purple coloration from midsummer on; elliptic to broadly oval to obovate, 5 to 15 cm long, 3 to 8 cm wide; apex acute to broadly rounded, margin entire, base wedge-shaped. Flowers unisexual, less than 4 mm in diameter, appearing in April before leaf expansion. Fruit a black drupe 8 to 10 mm long, 1 to 3 on pedicels 3 to 5 cm long, stone faintly ribbed.
Black Tupelo; blackgum/Nyssa sylvatica
Bark gray to brownish, divided into narrow, deep furrows and ridges of equal width. Branches stout, wide-spreading. Twigs 3 to 6 mm in diameter. Buds (terminal) broadly ovoid consisting of 4 appressed scales, dark brown to black; lateral buds spherical, tightly appressed to a crescent-shaped leaf scar. Leaves opposite, deciduous, odd-pinnately compound; 20 to 30 cm long, white below when fresh; leaflets 7 to 9, petiolulate, oval to ovate, 5 to 15 cm long, 3 to 5 cm wide, apex acuminate, margin essentially entire, base broadly rounded, pinnate veins conspicuous on underside. Flowers unisexual (plants dioecious); pistillate inconspicuous about 1 mm in diameter, arranged in dense paniculate clusters; staminate conspicuous in mass. Fruit a samara, 25 to 60 mm long, wing terminal on the thickened seed.
White Ash/Fraxinus americana
Bark brownish, smooth when young, then breaking into narrow ridges with shallow narrow furrows. Branches drooping to spreading and ascending. Twigs stout, 4 to 6 mm in diameter, olive green. Buds terminal black; smaller lateral buds tightly appressed to the generally straight upper edge of the leaf scar. Leaves opposite, deciduous, odd-pinnately compound with 5 to 7, occasionally 9, leaflets; leaflets narrowly to broadly elliptical, apex acuminate, margin entire to finely serrate, base wedge-shaped, hairy below along the veins. Flowers unisexual (plants dioecious); pistillate inconspicuous in open panicles; staminate in compact conspicuous clusters. Fruit a samara 25 to 50 mm long, seed end conspicuously slender and extending about half the length of the samara, wing decurrent on seed end.
Green Ash/Fraxinus pennsylvanica
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Acuminate. Gradually tapering to a pointed apex.
Acute. Having the shape of an acute angle.
Aggregate. A cluster of ripened ovaries traceable to separate pistils of the same flower and inserted on a common receptacle.
Anther. The pollen-bearing portion of the stamen.
Anthesis. Time of flowering.
Apetalous. Without petals.
Apex. The tip of leaf, twig, or other plant part.
Apical. Pertaining to apex.
Ascending. Growing obliquely or indirectly upward from point of attachment.
Axil. Upper angle between a leaf or other plant part and the stem to which it is attached.
Bisexual. Having both sex organs on the same plant; a hermaphrodite.
Blade. The flat expanded portion of a leaf or parts of a compound leaf.
Catkin. A flexible, usually pendulous, scaly spike bearing unisexual flowers.
Ciliate. Having a margin fringed with hair.
Compound Leaf. A leaf with two or more separate leaflets.
Cordate. Heart-shaped with the point at the terminal end.
Crenate. Having a margin with rounded to blunt teeth.
Cuneate. Wedge-shaped.
Deciduous. Not persistent; said of leaves falling in autumn or of floral parts falling after anthesis.
Dehiscent. Opening by bursting or splitting.
Dentate. A margin with sharp teeth pointing outward.
Dimorphous. Occurring in two forms.
Dioecious. Unisexual, with staminate and pistillate flowers on separate plants.
Drupe. A simple one-seeded fleshy fruit, the outer wall fleshy, the inner wall bony.
Entire. Margins without teeth or lobes.
Evergreen. Having green leaves throughout the year.
Falcate. Sickle- or scythe-shaped.
Follicle. A dry, single-carpel fruit, opening along one side for seed dispersal.
Fluted. Regularly marked by alternating ridges and grooves.
Fruit. The seed-bearing product of a plant.
Glabrous. Smooth, devoid of hair or surface glands.
Glandular. Furnished with glands, or glandlike.
Glaucous. Covered with a white waxy or powdery bloom.
Globose. Spherical, globular.
Husk. Fleshy covering of nut in hickories.
Imbricate. Overlapping.
Leaflet. A single division of a compound leaf.
Membranous. Thin, more or less flexible, translucent.
Midrib. The central rib or central vein of a leaf or similar structure.
Monoecious. Having unisexual flowers, with both sexes borne on the same plant.
Nut. A hard-shelled, indehiscent, usually one-celled, one-seeded fruit.
Oblique. Slanted; of unequal-sided or non-symmetrical leaves or leaf bases.
Obovate. Inverted ovate.
Obpyriform. Inverted pear-shaped.
Obtuse. Blunt.
Odd Pinnate. Pinnately compound with a terminal leaflet.
Ovate. Having the lengthwise outline of an egg, broadest at the base.
Ovoid. Egg-shaped in 3-dimensions.
Ovule. An embryonic seed in the ovary of a flower.
Palmate. With veins or lobes radiating from a common center.
Panicle. A compound or branched raceme.
Paniculate. Borne in a panicle.
Parted. Divided by sinuses which extend nearly to the midrib.
Perfect. Having stamens and pistils in the same flower.
Persistent. Remaining attached.
Petiolate. Having petioles, not sessile.
Petiole. The stalk of a leaf.
Petiolulate. Having petiolules.
Petiolule. The stalk of a leaflet in a compound leaf.
Pinnate. Descriptive of compound leaves with the leaflets arranged on opposite sides along a common rachis. Also used to describe leaf venation.
Pistil. The seed-bearing organ of the flower.
Pistillate. Provided with pistils; usually descriptive of unisexual flowers.
Polygamous. Bearing perfect and unisexual flowers on the same plant.
Polymorphic. Having two or more forms.
Pubescent. Covered with fine, soft, short hairs.
Pyriform. Pear-shaped.
Raceme. An inflorescence consisting of a central rachis bearing a number of flowers with stalks of nearly equal length.
Rachis. The axis of a compound leaf or inflorescence.
Receptacle. The portion of the floral axis upon which the flowers are borne.
Reticulate. Forming a network.
Rhombic. Somewhat diamond-shaped.
Rib. A prominent vein.
Samara. An indehiscent winged fruit.
Scurfy. Covered with small scales.
Seed. A ripened ovule.
Serrate. With sharp teeth pointing forward.
Sessile. Without a stalk of any kind.
Simple. Of one piece; not compound.
Sinuate. Deeply or strongly undulate or wavy.
Sinus. A recess, cleft, or gap between two lobes.
Spatulate. Spatula-shaped.
Spike. An inflorescence consisting of a central rachis bearing a number of stalkless flowers.
Stamen. Pollen-bearing organ of the flower.
Staminate. Bearing stamens.
Stellate. Star-shaped.
Stipule. A leafy appendage attached to the twig at the base of a petiole; usually in pairs, one on each side, often shedding early.
Striate. With fine grooves, ridges, or lines of color.
Suture. Line of dehiscence.
Subglobose. Globe shaped, but slightly flattened.
Subsessile. Almost stalkless.
Tomentose. Coated with short, matted woolly hair.
Truncate. Having a blunt tip or end, appearing as if abruptly cut off transversely.
Undulate. Wavy.
Unisexual. Having stamens and pistils in separate flowers.
Valvate. Opening by valves as in a capsule or some leaf buds; meeting at the edges without overlapping.
Whorl. Circular arrangement of appendages at a node.
Woolly. Clothed with long, matted hairs.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Brown, C. A. and H. E. Grelen.
1977. Identifying hardwoods growing on pine sites. USDA For. Serv. Gen. Tech. Rep. SO-15, 69 p. South. For. Exp. Stn., New Orleans, La.
This publication illustrates and describes 26 hardwood species or varieties, including 16 oaks and hickories, with photographs of leaves, bark, buds, flowers, and fruits. Line drawings feature the winter silhouette of each species and a key is included to assist in identification.
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