3Outdoor Classroom Institute 2004 Forested Ecosystems
4IntroductionStudy of forests requires knowledge of the species that compose them but……..Leaves of forest trees are often inaccessibleSpecies must be identified primarily by their bark and fruit as leaves are too far away for careful examinationHere we use photographs of bark for identification
8Bark Thickness Bark on many trees is quite thin. Examples would be American Beech, Black Cherry and IronwoodThin Barked trees generally do not have a lot of texture in their barkThick Barked trees include ash, walnut, and yellow poplar.All trees develop thicker bark with age.
9Bark TightnessThis is a measure of how firmly attached the bark is to the woody tissue.It is not related to bark thickness as Oaks have thick bark but bark that is also very tight.If the Bark is exfoliating, shredding and scaling off then the bark would be said to be loose
10Bark PatternBark consists of ridges and valleys or fissures separating themSome have wide fissuresSome have narrow fissuresSome have fissures “painted white”Thin barked trees can have pigment-based patterns. For example tree of heaven has diamond-shaped patches.
11Eastern Red CedarJuniperus virginiana, is our only native cone bearing tree. This species is the source of cedar lumber so often used in cedar chests. It is identifiable by its shreddy reddish bark and by the persistence of dead limbs on the lower part of the tree. Leaves are scale-like.
12Black WillowSalix nigra, is a wetland species that is common along streams and lakes. At Clay Hill it occurs only where the soil is persistently wet. Bark is black and deeply furrowed with scaly ridges. Leaves are 3-6 inches long and lance shaped.
13Walnuts (Juglandaceae) Alternate pinnately compound leavesFruit encased in a fleshy huskTwigs with chambered pithSpecies of forest openings and gaps intolerant of shade
14Black WalnutJuglans nigra, has compound alternate leaves, deeply furrowed reddish black bark superficially resembling ash. Bark of walnut is layered as seen in the insert on the left. Walnuts are usually found near these trees. Twigs have chambered pith.
15ButternutJuglans cinerea, white walnut is identifiable by its sinuous dark ridges that separate flat white patches between. The leaves are walnut-like. The nut looks like an elongated walnut. The roots of larger trees are distinctively buttressed
16Hickories (Juglandaceae) Alternate pinnately compound leavesNut enclosed in a woody huskPith solid
17Bitternut HickoryCarya cordiformis, has bark that contains shallow furrows and ridges that are more or less parallel to one another. Fruits are about 1 “ or less and distinctively winged. This species has sulfur yellow buds and yellowish color on the nuts. Bitternut differs from the other hickories because its buds are slender.
18Pignut HickoryCarya glabra, resembles bark of mockernut hickory but differs in having 5 leaflets rather than 7-9. and in the size and shape of the nut. Pignut fruits are smaller than those of either mockernut or shagbark. They also are differently shaped being somewhat oval with an elongate stem such that they appear pendant.
19Mockernut HickoryCarya tomentosa, is one of three so-called tight-barked hickories we have at CHMF. Its bark is fissured. The fissures are arranged such that the ridges between them appear braided or interlaced. The tree has compound leaves with 7-9 leaflets. Nuts of this species are large (1 1/2 -2 inches) and similar to those of shagbark hickories.
20Shagbark HickoryCarya ovata, is a common, easily identified forest tree. The only other tree with such shaggy bark is the kingnut hickory and it is a bottomland species. Leaves have 5-7 leaflets. Winter buds are quite large to ¾ “. Nuts are edible and a favorite of humans and squirrels alike
21Birches (Betulaceae) Leaves alternate and simple Leaf edges serrated Generally small treesTwo woodland species, hornbeam and eastern hornbeam both also called ironwood. Both species are slow growing understory trees.
22Hop Hornbeam (Ironwood) Ostrya virginiana, is a distinctive understory tree seldom reaching a diameter of 10 “ or more. Ironwood has a distinctively shreddy bark, oval unlobed leaves with saw-toothed edges and a distinctively hops shaped fruit in autumn.This species is one of the slowest growing species in the forest. This slow growth makes growth rings incredibly small and the wood incredibly hard.
23BluebeechCarpinus caroliniana, has bark that resembles American beech, but it has a very sinuous appearance. Bark is often mottled with light and dark patches. The photograph was taken when this tree was wet so it appears darker than it normally would
24American BeechFagus grandifolia, is one of the more easily identified trees. This large forest species has thin gray bark that does not change much with age. It gets covered with patches of algae and lichen occasionally giving it a greenish tint. The leaf edges are serrated and the leaves are ovate in shape.In winter the buds are very elongate and sharp, often resembling needles or awns.
25Oaks (Fagaceae) Leaves simple and alternate Leaves have highly variable marginsFruit is an acornAcorn shape and size is species-specificTerminal buds are clustered at the end of stemsPith is obviously star-shaped
26White vs Red Oaks White Oaks Red Oaks Leaf edges are smooth or scallopedAcorn matures in one yearNut shell smooth insideRed OaksLeaf lobes commonly sharp and bristle tippedAcorn matures in two years.Nut shell woolly inside
27White OakQuercus alba, is one of the more important trees in forests of Kentucky. This species is easily identifiable by is light gray color, by its relatively thin bark and by shreddy nature of its bark.Leaves are distinctively lobed and its acorns are quite small (~1/2 “) relative to those found in red oaks.
28Black OakQuercus velutina, is a large forest tree with dark bark that is very hard and deeply fissured. In older trees the fissures fragment horizontally forming a bark with a very blocky appearance. Leaves resemble those of red oak but have flat bases. Acorn is distinctive with cup covering ½ of nut and having loose scales. Kernel is yellow
29Northern Red OakQuercus borealis, is an important, large forest species. Its bark is similar to that of most other red oaks except that in the younger branches there are silvery streaks between darker patches.Northern red is also easily identifiable by its distinctive acorn which is ¾-1 inch in length and capped by a saucer shaped cup.
30Shumard OakQuercus shumardii, leaves are more distinctive than the bark or acorn. Leaf notches or sinuses tend to be narrower at the edge of the leaf than they are closer to the mid-vein. Bark most closely resembles that of black oak. Acorn cup is shallow and identifiable by elongate pointed scales.
31American ElmUlmus americana, was one of our largest forest species until the introduction of Dutch Elm Disease. Now most of the trees are small. It is recognizable by having thinly fissured bark with ridges between these fissures flakey. The general color is brownish red. The tree is also identifiable by its distinctive simple leaves. They are ovate and serrate-edged with uneven, asymmetrical bases.
32HackberryCeltis occidentalis, is common in fencerows and other openings but not common in woodlands. Younger trees have bark that is similar to American Beech but as they age the develop warty ridges of layered bark. Leaf base is uneven or lopsided.
33Yellow Poplar (Tulip Tree) Liriodendron tulipifera, is a very common species at CHMF. This straight tall tree is characterized in younger species by shallow white-colored patches between narrow ridges. Also the tree leaves triangular limb scars as the lower limbs are lost. In the spring this member of the magnolia family has showy yellow flowers that eventually produce a winged fruit.
34SassafrasSassafras albidum, is a distinctive tree young or old. This specimen is quite large. Its bark has a reddish cast and a distinctive spicy odor. It is deeply furrowed and blocky. Younger trees are identifiable because the new twigs are green in color and the leaves have distinctively two or tree different shapes.
35SycamorePlatanus occidentalis, also known as the plane tree is one of the larger trees in North America. This species has thin peeling bark with patches of white in younger branches. It requires substantial moisture and can be considered a wetland species.
36Black CherryPrunus serotina, is a common forest species that is easily identifiable by its black scaly bark. It has a thin platy appearance. Leaves are simple, serrate and alternate. Fruit is a small (1/4 inch) black cherry.
37Eastern RedbudCercis canadensis, is a small understory tree with thin orange tinted bark that becomes scaly with age. Leaves are heart shaped. Flowers are pink-red in early spring. Seeds are born in a pod-like fruit .
38Tree of HeavenAilanthus altissima is an introduced species. Its origin is China and it has fast become one of the most invasive of introduced trees.Tree of heaven has a thin gray to black bark with diamond-shaped markings and a generally sooty appearance. Leaves of this species are pinnately compound and they possess a distinctively foul odor. Leaflets have a small projection or yellowish gland at their base.
39Sugar MapleAcer saccharum, is the source tree for hard rock maple furniture and maple syrup. Maples all have opposite leaves, winged fruits. Bark is incredibly variable but generally has long scaly plates. Red maple has bark broken up into smaller scaly plates.
40Red MapleAcer rubrum, is a common forest tree with oppisite serrate edged leaves. The bark in this tree is much more similar to that of silver maple (water maples that is often used as a shade tree because of its rapid growth.
41Yellow BuckeyeAesculus octandra, is a distinctive tree. Its bark is thin and platy and almost always covered with mosses and algae. Its leaves are compound with leaflets arranged like the fingers of a hand (palmate). This species is shade tolerant. It occurs at moist sites.
42Black Gum (Tupelo)Nyssa sylvatica, is one of two species with “alligator bark”. It is deeply fissured vertically and horizontally such that it is quite blocky in appearance. The edges of these irregularly-shaped blocks are often rounded over. Tupelo leaves are among the first to change colors in the fall. Generally they are bright crimson red.
43Flowering DogwoodCornus florida, is perhaps our most common understory tree. It is recognized by opposite simple leaves. The bark is thin, reddish and broken into squarish plates somewhat similar to black gum but the fissures are much shallower in dogwood
44PersimmonDiospyros virginiana, is one of very few species in which the bark of young trees is broken into squarish blocks. Its leaves are untoothed, oval-shaped and net-veined. Its twigs are distinctive because they have distinctive bundle scars.
45White AshFraxinus americanus, is one of the few species of tree with opposite compound leaves. The bark varies from having regular diamond shaped ridges to having the irregular fragmented appearance of the tree figured here. The outer bark of ash is spongy when pressed with the thumbnail.
46No attempt was made here to include every tree No attempt was made here to include every tree. It is my hope that I have included the more common species. It is also my hope that this project will serve as incentive for you to adapt this program for use with your particular grade level. You may freely use the images for educational purposes. If you find a good use for them I would appreciate seeing what you have done. me at or better yet, stop by CHMF for a longer visit.