Forest Treesof Wisconsin

How to Know Them

PRINTED ON RECYCLEDPAPER

Published by the Departmentof Natural ResourcesMadison, WisconsinDivision of Forestry

The Wisconsin Department of Natural Resources provides equalopportunity in its employment, programs, services, and functionsunder an Affirmative Action Plan. If you have any questions,please write to Equal Opportunity Office, Department of Interior,Washington, D.C. 20240.

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Dedicated to the memory ofF.G. Wilson

Table of Contents

Forward

Introduction

Conifers (soft woods)Cedar, northern white (arbor vitae) . Thuja occidentalis ................... 1

Cedar, red (juniper) ......................... Juniperus virginiana ............... 2

Fir, balsam ...................................... Abies balsamea ....................... 3

Hemlock .......................................... Tsuga canadensis ................... 4

Pine, jack ......................................... Pinus banksiana ..................... 5

Pine, red (norway pine) ................... Pinus resinosa ......................... 6

Pine, white ....................................... Pinus strobus .......................... 7

Spruce, black ................................... Picea mariana ........................ 8

Spruce, white ................................... Picea glauca ............................ 9

Tamarack (American larch) ............. Larix laricina ......................... 10

Deciduous Trees (hardwoods)Ash, black ........................................ Fraxinus nigra ....................... 11

Ash, green ....................................... Fraxinus pennsylvanica ......... 12

Ash, white ........................................ Fraxinus Americana ............... 13

Ash, mountain ................................. Sorbus Americana .................. 14

Aspen, big-tooth .............................. Populus grandidentata .......... 15

Aspen, quaking ............................... Populus tremuloides .............. 16

Balm of Gilead (balsam poplar) ...... Populus balsamifera .............. 17

Basswood (linden) ........................... Tilia americana ..................... 18

Beech ............................................... Fagus grandifolia ................... 19

Bluebeech (hornbeam) .................... Carpinus caroliniana ............. 20

Birch, paper ..................................... Betula papyrifera ................... 21

Birch, river ....................................... Betula nigra ........................... 22

Birch, yellow .................................... Betula lutea ........................... 23

Box elder ......................................... Acer negundo ......................... 24

Butternut ......................................... Juglans cinerea ...................... 25

Cherry, black ................................... Prunus serotina ...................... 26

Cherry, choke ................................... Prunus virginiana .................. 27

Cherry, pin ....................................... Prunus pennsylvanica ............ 28

Cottonwood, eastern ....................... Populus deltoides ................... 29

Elm, American ................................. Ulmus Americana .................. 30

Elm, rock ......................................... Ulmus thomasii ..................... 31

Elm, slippery (red elm) .................... Ulmus rubra ........................... 32

Hackberry ........................................ Celtis occidentalis .................. 33

Hickory, bitternut ............................ Carya cordiformis .................. 34

Hickory, shagbark ........................... Carya ovata ........................... 35

Ironwood (hop hornbeam) .............. Ostrya virginiana ................... 36

Juneberry (service berry) .................. Amelanchier Canadensis ....... 37

Locust, black ................................... Robinia pseudoacacia ............ 38

Locust, honey .................................. Gleditsia triancanthos ........... 39

Maple, red (soft) .............................. Acer rubrum ........................... 40

Maple, silver (soft) ........................... Acer saccharinum .................. 41

Maple, sugar (hard) ........................ Acer saccharum ..................... 42

Oak, black ....................................... Quercus velutina .................... 43

Oak, bur .......................................... Quercus macrocarpa .............. 44

Oak, chinkapin ................................ Quercus muehlenbergii .......... 45

Oak, northern pin(hills oak or jack oak) ................. Quercus ellipsoidalis .............. 46

Oak, red .......................................... Quercus rubra ........................ 47

Oak, swamp white ...........................Quercus bicolor ...................... 48

Oak, white ....................................... Quercus alba ......................... 49

Plum, wild ....................................... Prunus americana ................. 50

Walnut, black .................................. Juglans nigra ......................... 51

Willows ............................................ Salix species ........................... 52

Key to Wisconsin TreesSign Posts to Identifying Trees ........................................................ 53

How to Prevent Forest Fires ............................................................. 57

How Forest Fire Danger Is Measured .............................................. 58

What Causes Forest Fires to Start? .................................................. 59

Wildlife & Forests ............................................................................ 60

Note: Illustrations are not drawn to scale.

“Forest Trees of Wisconsin” wasfirst published in 1928.It was written by F. G. Wilson,one of the eleven original forestrangers hired by the state in1911. Fred Wilson, along withseveral other foresters, was oneof the original pioneers of forestmanagement in Wisconsin. Hewas the first to use seedlings toreplant forest stands and wasinstrumental in developing thestate forest nurseries for thispurpose. The wisdom of Fred’spioneering efforts culminatedin his planting the onebillionth tree from the statenurseries in 1979.

Seventy-seven years after thefirst publication of this book,the words written in theoriginal Forward are stillpertinent today:

“Trees are important to Wisconsinlandscapes from the standpoint ofbeauty as single specimens or in-groups. In forest and farmwoodlands, they are vital tools forthe stabilization of the soil and inslowing water runoff. Forests areour largest public hunting andfishing grounds and producewildlife and recreational benefitsas well as timber crops.

In the near future the capitalizedvalue of Wisconsin’s forest will beabout a billion dollars and thevalue of a single year’s crop offinished forest products mayexceed this amount in a singleyear. It is evident that we mustcontinue to protect these forestsfrom fire, insects and disease andall citizens should cooperate inthis program.”

Today, forestry in Wisconsin isvitally important to oureconomy as well as ouroverall well-being.

Wisconsin’s forest industry isthe 2nd largest employer in thestate. We are the leading statein paper production and aleader in the production ofhigh quality veneer andsawlogs. But, most importantly,Wisconsin’s forests aremanaged in a way thatguarantees the scenery,recreation, wildlife, waterquality and aesthetic benefitsits citizens demand.

“The man who has a piece ofwoodland where during the wintermonths he cuts firewood andfencing, and a few logs for therepair of building and imple-ments, and during certain yearswhen prices are high cuts somelogs for the neighboring sawmill,but at the same time looks afterthe piece of woods, clears it ofdead timber and other rubbish,thus keeping out fire and insects,and otherwise makes an effort tokeep the land covered with forest -such a man practices forestry. Hisforest may be small or large, hisways of doing may be simple andimperfect, the trees may not bethe best kind for the particularlocality and soil, they may not beas thrifty as they should andcould be; but nevertheless here isa man who does not merelydestroy the woods nor contentshimself with cutting downwhatever he can sell, but one whocares for the woods as well as usesthem, one who sows as well asharvests. He is a forester, and hiswork in the woods is forestry.”

Filibert Roth - From theoriginal printing, 1928

Forward

Introduction

Trees, like all living thingsgrow and mature and die,while the forest, which is, acommunity of trees, may liveindefinitely, because the treesreproduce before they die.

VegetativeReproductionMany trees reproducevegetatively under certainconditions, for example, mostof the broad leaf trees willsprout if cut when small, whilesome like basswood will sproutregardless of age. Others likethe quaking aspen and blacklocust will send up shoots fromthe roots at considerabledistance from the parent tree.

The only American conifer(cone-bearing tree) whichsprouts is the redwood, but wehave one conifer in Wisconsinwhich often reproducesvegetatively, but by a methodother than sprouting. Lowerlimbs of black spruce oftentouch the ground and, wheremoss grows over the limb backof the tips, roots develop, andfinally the tip of the branchbecomes a new tree.

Man uses the ability of sometrees to reproducevegetatively. Cuttings fromsmall branches of willow oreastern cottonwood bearingseveral buds can be set in theground to grow, because theywill develop roots. Othermethods like budding andgrafting are used to propagatehorticultural varieties. Wecannot grow Baldwin appletrees from seed, but must grafta twig from a Baldwin treeonto a seedling apple tree.

Reproductionby SeedHowever, most of our foresttrees grow from seed and theway the seeds are produced isthe basis for classifying plants.For example, white pine seedsgrow in pairs on the innersurface of the cone scales,while the hickory seed isenclosed in a nut. This reallyis the difference between theconifers or evergreens, and thebroadleaf trees.

In this bulletin the word“fruit” is used in the botanicalsense, meaning the seeds andseed bearing part, therefore,the acorn and its cup togetherconstitute a fruit.

The Formationof Seed Some seed is produced from“perfect” flowers, like thecherries where both stamensand pistils are found in thesame tree. This is bestillustrated with the corn plant,where the tassel or staminateflower produces the pollenwhich must fertilize the grainsin the ear. You have all seenears of corn where some of thekernels did not developbecause they were notfertilized by pollen.

With some species like theashes and the poplars, sometrees have only staminateflowers and others onlypistillate flowers, so that thefemale trees will not bear seedunless there are staminatetrees in the vicinity. TheLombardy poplar which is ahorticultural variety of theEuropean poplar never bears

seed because the variety wasdeveloped as a mutation andthere are no Lombardypoplars bearing staminateflowers. Therefore, it is alwaysreproduced vegetatively; thatis, by cutting or sprouts.

Distribution of SeedSince some trees mature theirseed in spring while othersripen later, seeds developedseveral methods of scatteringor planting themselves. Seedsfrom the aspens are very lightand so perishable that theymust come in contact withmoist mineral soil within afew hours. As they arecovered with cottony downthey are carried by the wind.These two characteristics haveenabled the aspen to reforestmany of the burned overareas. Pin cherry also comesin on areas after forest firesbecause birds eat the cherriesand may drop the seed farfrom the parent tree.

Seeds of pine, maple andbasswood have wings so thatthey are carried farther bywind, while the heavy nutsand acorns are often buriedby squirrels and thenforgotten. Seeds of trees whichgrow along the stream banksare carried by the water.

Jack pine is especiallyinteresting because it protectsits seeds from fire. While mostof the cones will open the firstautumn, a few will remainclosed, sometimes for manyyears. Then following a forestfire, these cones will openfrom the heat and drop seedson the denuded land. In thisway jack pine predominateson lands which originallycarried mostly Norway orwhite pine. If jack pine grows

in your vicinity look for someof these unopened cones andplace one on a hot stove andwatch the scales open.

How Trees GrowThe growth of new wood inany year forms a completelayer over the entire tree. Thatis why we can determine theage of a tree from the numberof rings on the stump. Heightgrowth occurs only in the newwood of any one year. If anail is driven into the trunk ofa ten foot tree at five feet fromthe ground, it will still be fivefeet from the ground when thetree is a hundred feet tall.

The form of trees depends onthe growing space. A closespacing between trees, shadesthe tree stems by restrictingsunlight and causes sidebranches to die and fall off,leaving tall straight cleanstems which are valuable fortimber. Shade trees which haveroom to spread out have alarge crown with spreadinglimbs and a short stem. Noticethe trees at the edge of a forest,they have branches on the sidetowards the open while theother side is free of branches.

Variations in TreesSince form and size or colorand character of bark varywith size and growingconditions, too muchimportance should not beplaced on them in identifyingtrees. The leaves from thelower branches of a tree mayhave a very different outlinethan those from the tip of thetree, while leaves on thesprouts from a tree which wascut may be excessively largeand of unusual shape. Noticethe difference between the

twigs and needles of balsamtrees when one has had fullsunlight and the other grew inthe shade.

An effort has been made topoint out several distinguish-ing characteristics in describ-ing each tree. After you haveidentified the trees, they canbe recognized as you recog-nize your friends on the streeteven though you cannotdescribe them so that astranger will recognize them.

1Northern White Cedaror Arbor Vitae

(Thuja occidentalis)

FormCompact pyramidal; height50 to 60 feet and 2 to 3 feet indiameter; trunk oftenbuttressed, strongly taperedand frequently divided into2 or more direct stems;branches short and nearlyhorizontal; sometimes formsalmost impenetrable thickets,as dead branches are very stiffand persistent; in the open,develops a conical,symmetrical crown.

BarkThin, gray to reddish brown,separating in long, vertical,narrow shreddy strips.

LeafScale-like; length 1⁄8 or 1⁄4inches, arranged to make thesmall branches flat; pleasant,aromatic scent when crushed;pungent to the taste.

FruitSmall, oblong cone thatmatures in one season;yellowish-brown; 1⁄3 to 1⁄2inches in size, with 6 to 12

scales; borne singly or in largeclusters on ends of branches.Seeds 1⁄8 inch long, with 2narrow wings almost circlingthe seed.

RangeFound throughout the state,except the southwest portion;grows usually in moist placeswhere it is often found indense pure stands; however,farther north it appears onwell-drained slopes, usually inmixtures with hardwoods.

WoodLight, soft, brittle, coarsegrained, durable, fragrant andpale brown in color; especiallyimportant for making fenceposts, building poles, rot-resistant lumber and shingles.

NotesIt is one of the preferred andimportant species for deerbrowse in the winter. Thereare numerous ornamentalvarieties.

2 Red Cedar or Juniper(Juniperus virginiana)

FormStraight trunk, sometimeshaving lobed appearance;crown is pyramidal, becomingrounded; height 25 to 30 feetwhen growing in goodlocations; seldom exceeds1 foot in diameter; may bemulti-stemmed or nearlyprostrate on poor, rockyand dry sites.

BarkThin, reddish brown, peelingoff in long, vertical shred-likestrips.

LeafTwo kinds, usually found onsame tree; more common kindis dark green, minute andscale-like, clasping the stem in4 ranks so that the stemappears square; second kindusually appears on youngtrees or vigorous shoots, areawl-shaped, quite sharp-pointed, spreading andwhitened on underside.

FruitA dark blue berry-like cone;diameter 1⁄4 inch, enclosing 1to 4 seeds in the sweet flesh;matures in 1 season.

RangeDry, gravelly soil, and rockyledges in southern half ofstate; most abundant onlimestone ridges insouthwestern part of statewhere few other trees arefound. One of the first trees toinvade abandoned fields.

WoodRed, fine-grained, soft, weak,fragrant and very durable;used for interior woodwork,chests, closets, lead pencils,posts and poles.

NotesIs a favorable winter food forsome birds. Red cedar spreadscedar apple rust; therefore it isnot favorable to plant in ornear orchards or anywhere inregions devoted to commercialapple production.

3Balsam Fir(Abies balsamea)

FormMedium size, attainingheights of 40 to 60 feet anddiameter of 1 to 2 feet; short-spreading branches form ahandsome, symmetrical,spire-like crown.

BarkThin, smooth, grayish,prominently marked byblisters filled with resin orbalsam pitch.

LeafNeedle-like, stalkless and flat;length 1⁄2 to 1 inch withrounded point, dark greenand lustrous above and silverywhite bands beneath; twisted;2-ranked arrangement ontwig; resinous and fragrant.

FruitCones upright on branches,purple, oblong; length 2 to 4inches; becomes mature infirst year; seeds when ripe falltogether with scales of cone,leaving hard central axisstanding upright on branchlike a spike.

RangeFound in forests of thenorthern half of Wisconsin;usually in association withwhite spruce from which itcan easily be distinguished byits large upright cones andsoft leaves; thrives in cool,moist, or shaded places.

WoodLight brown, soft, not strongor durable; coarse grained; isused mainly for paper pulp;also an important Christmastree. The oleoresin from thepitch blisters on the bark is“Canada Balsam,” much usedin optical instruments,microscopic slides, etc. astransparent cement for glass.

NotesTwo serious insect pests occuron balsam fir: the sprucebudworm and balsamwoody aphid.

4

FormHeight 60 to 100 feet anddiameter of 2 to 4 feet;branches spreading and nearlyhorizontal; pyramid-shapedwith drooping top shoot inyoung trees and with roundedtop on large, mature trees.

Bark1⁄2 to 3⁄4 inches thick; varyingfrom cinnamon-red to gray incolor; with deep furrowsseparating the broad,flattened scales.

LeafNeedles 1⁄3 to 2⁄3 inches inlength; flat; rounded tonotched at tip; yellowish-greenwith 2 whitish bandsunderneath; a 2-rankedarrangement; twigs roughenedby woody, raised projections(sterigmata) where needlesattach to twigs. Most buds arescaly and not resinous.

Hemlock(Tsuga canadensis)

FruitCones 1⁄2 to 3⁄4 inches inlength; scales thin and almostas broad as long; matures inone season. Seeds are winged,slightly resinous and about1⁄16 inches long.

RangeNative to northeastern quarterof the state, isolated standsoccur on cool north slopes inColumbia, Sauk and Vernoncounties. It grows on thebetter and moister soils, oftenin mixtures with hardwoods.

WoodLight reddish-brown; soft,coarse, brittle, splintering, andnot durable; often manufac-tured into coarse generalconstruction lumber.

NotesHeavily browsed by deer;inner-bark once used fortanning leather; oil of hemlockdistilled from young branches.

5Jack Pine(Pinus banksiana)

FormHeight 50 to 70 feet;diameter rarely exceeds 2feet; open, conical shapedcrown; often retaining deadbranches on trunk all theway to the ground.

BarkDark brown, irregularly dividedby furrows into small scales.

LeafNeedle length about 1 inch;light to dark yellow-green;sharply-pointed; two in abundle and slightly twisted.

FruitCones – length about 11⁄2inches; 2 years to maturity;often strongly curved, brownwhen ripe, turning gray later;resinous; sometimesremaining on branchesunopened and containinggood seeds for many years;small-winged triangular seedswhich may be carried far instrong winds. Many treesbegin producing cones asearly as 7 years old.

RangeFound commonly on the sandysoils of the northern half of thestate, and extends downwardalong the Wisconsin River toIowa and Grant counties.

WoodLight, soft, not strong, closegrained, clear pale brownwith thick, nearly whitesapwood. Primarily apulpwood species but alsoused for laths, box materialand increasingly for lumber.

NotesDue to the resinous nature ofits cones, jack pine is usuallyone of the first tree species tooccupy a site after fire.

6 Red or Norway Pine(Pinus resinosa)

FormHeight is usually 80 to 90 feet;occasionally 120 feet tall; 2 to3 feet in diameter; brancheson mature trees form an open,rounded, picturesque crown.

BarkBecomes divided into large,reddish brown plates as itmatures, which gives trees itscharacteristic appearance andone of its common names,red pine.

LeafNeedles in clusters of 2; darkgreen to yellow-green; 4 to 6inches long; brittle (easilybroken when doubled betweenthe fingers); needle sheathpersistent.

FruitCone about 2 inches inlength. The thin, slightlyconcave cone scales arewithout spines or prickles andare free from resin. Conesshort stalked to nearly sessile.Like all pines, it requires2 years for cones to mature;

cones are purplish in colorwhen ripe; seeds small, lengthabout 1⁄8 inch, dark or mottledbrown, winged and widelyscattered by the wind.

RangeFound in pure stands in manyparts of northern Wisconsinand isolated stands occur asfar south as Dane County. It isusually found on sandier soilsthan white pine. Increasing inpopularity for forest plantingbecause of its general freedomfrom disease and insect attack.

WoodPale red with thin, nearlywhite sapwood; moderatelyhard, close grained and usedmainly for pulpwood.Increasingly being used forconstruction lumber, pilingsand pressure-treated poles.

NotesOften called Norway pine. Redpine is a fast growing speciesand needs full sunlight forbest growth and development.

7White Pine(Pinus strobus)

FormThe straight stem, regularpyramidal form and soft gray-green foliage make it one ofthe most majestic trees in thestate. The crown is composedof numerous whorls ofhorizontal or ascendingbranches that are plume-likeand graceful in outline. Atmaturity, it reaches heights of100 feet and diameters of 2 to3 feet. White pine may still befound up to 150 feet in heightand up to 4 feet in diameter.

BarkThin, smooth, resinous andgreenish-gray on young trees,but thick and deeply fissured andgrayish-brown on older trees.

LeafNeedles 3 to 5 inches long;bluish-green; flexible; occur inbundles of 5, which distin-guishes the trees from othernative pines in Wisconsin;needle sheath deciduous.

FruitCones are 4 to 6 inches long,cylindrical, with thin andusually very resinous scales,each containing two smallwinged seeds. Cones some-what curved. Cones mature in

August or September of thesecond season.

RangeOccurs naturally throughoutnearly the entire state. Itgrows on sandy soils and rockridges, but prefers fertile, well-drained soils.

WoodLight, soft, weak, light brownin color, often tinged with red;easily worked; manufacturedinto matches, lumber andlaths; used for constructionpurposes (cabinet and windowmaking, interior finish ofbuildings and wooden wares).

NotesWhite Pine Blister Rust andWhite Pine Weevil continue tobe a problem in the state.White pine is very susceptibleto air pollution damage. It isintermediate in tolerance toshade and thus generallyoccurs as a temporary orintermediate (though long-lived) species in forestsuccession. White pine is amajor dominant in Wisconsin’snorthern dry forests. It is thelargest and longest-livedspecies of the region.

8 Black Spruce(Picea mariana)

FormSmall tree seldom exceeding 60feet in height and 1 foot indiameter in Wisconsin and isoften a stunted tree, less than30 feet high. The crown isdense, narrow, and conical inform, with dropping branches,extending nearly to the ground.

BarkThin and broken on surfaceinto thin gray-brown scales.

LeafNeedles, bluish-green, short,pointed, four-sided; length 1⁄2inch; arrangement of needleson branch not two-ranked.

FruitCones oval shaped; lengthabout 1 inch, matures in oneseason, light brown in colorwhen ripe, after shedding seedin fall can persist on treesindefinitely. Seeds small,about 1⁄8 inch long, darkbrown and winged.

RangeFound in poorly drainedswamps and occasionally onwell-drained slopes innorthern Wisconsin. Oftenassociated with tamarack,balsam fir and white spruce.

WoodYellow-white, light, soft andmedium strong; used mainlyfor paper pulp.

9White Spruce(Picea glauca)

FormReaches 60 to 80 feet inheight; occasionally 100 feetwith a diameter of 2 feet. Thecrown is a broad-based, openpyramid, the rigid branchescurving upward. Except indense forests, the crownextends well down the trunk.

BarkThin, separating into light,gray-brown scaly plates.

LeafNeedles 4-sided and crowdedalong upper-half ofbranchlets; length 1⁄2 to 3⁄4inches; dark bluish-greenwhen mature; sharply pointed,having a slightly disagreeableodor when crushed.

FruitSlender cone, about 2 incheslong; matures in one season;light brown when ripe; conesusually drop during winterafter opening and sheddingseeds. Seeds 1⁄8 to 1⁄6 incheslong, pale brown, winged.

RangeExtensively found in forests ofnorthern Wisconsin. Thriveson moist, well-drained soilsand in swamps with balsamand tamarack; also foundassociated with mixedhardwoods.

WoodLight, strong, soft, straightgrained, yellow-white in color;used in the manufacture ofvarious products, mostimportant of which is paper.Largest trees are sawed intolumber and used for generalconstruction: airplanes,furniture parts, canoe paddlesand sounding boards formusical instruments; plantedquite extensively for orna-mental purposes, windbreaks,and shelterbelts; ranks high asa Christmas tree.

NotesSpruce budworm is causingextensive damage to thisspecies in the state.

10 Tamarack or Larch(Larix laricina)

FormHeight 30 to 60 feet, diameter1 to 11⁄2 feet.

BarkRough and separates on thesurface into thin, reddish-brown scales. Twigs are lightbrown and covered withnumerous tiny spurs orshort branches.

LeafNeedles flat, soft and slender;length about 1 inch; borne inclusters or spur-like branchesand distributed singly onterminal shoots; bright greenin spring, soft and flexible,turning dull yellow inSeptember or October justbefore falling; tamarack is theonly conifer in Wisconsin thatsheds all its leaves each fall.

FruitYoung cones red or greenish;mature cones light brown;width 1⁄2 inch, length 3⁄4 inch;nearly spherical; open in thefall of first year to liberatesmall, 1⁄8 inch, light brown,

winged seeds. Cones oftenremain on trees several yearsafter shedding seed.

RangeChiefly in swamps in northernpart of state in region ofconiferous forests;occasionally in drier localitieswhere it reaches largest size.Found scattered in coldswamps throughout thesouthern portion of the state.Often found in associationwith black spruce, balsam firand northern white cedar.

WoodLight yellowish-brown, heavy,hard and very durable incontact with soil; used forposts, poles, ties, pulpwoodand locally for lumber.

NotesLarge trees are rare as mostold specimens were killedyears ago by the larch sawfly.Crown has an open,pyramidal shape.

11Black Ash(Fraxinus nigra)

FormMedium-sized tree; height 50to 75 feet, diameter 1 to 2 feet.Forming an open crown ofnarrow, upright branches inthe forest.

BarkGrayish on older portions oftree, furrowed and somewhatseparated into thin scales thatare easily rubbed off. Whitelenticels appear on lowertrunk and roots.

LeafOpposite on stem; compound,consisting of 7 to 11 leaflets;leaflets oblong in shape,tapering to a point, and notstalked, except the terminalleaflet; leaflets sharplytoothed along edges; terminalbud is large and pointed.

FruitA samara, similar to that ofall ashes, except that the thinwing nearly surrounds theflattened seed. The wing isbroader than that of white orgreen ash, and the apex ofthe wing is distinctly notched.

RangeFairly well distributed overentire state; most abundant incold, moist locations andalong low banks of streams.Usually found in associationwith black spruce, balsam fir,white cedar and tamarack.

WoodDark brown, sapwood oflighter color, coarse grained,heavy; not as strong orvaluable as green or whiteash; easily separated into thinlayers furnishing excellentmaterial for baskets, hoops,etc.; also used for cabinetmaking and fence posts.

12 Green Ash(Fraxinus pennsylvanica var. lanceolata)

FormHeight 50 to 60 feet,diameter 2 feet or more;stout, upright, branchesforming a rounded crown.

BarkAbout 1⁄2 inch thick; darkbrown or gray, tinged withred; furrowed with flat,scaly ridges.

LeafLength 10 to 12 inches;compound, and opposite onstem; each compound leaf hasfrom seven to nine stalkedleaflets; leaflets 3-5 incheslong with apex pointed andslightly toothed on margin;differs from white ash inhaving leaf scars that aresemi-circular to crescentshaped, extending to base ofnew bud.

FruitA samara, borne in clusters ontree; length 11⁄2 to 2 1⁄4 inches,width 1⁄4 to 1⁄3 inches, withwinged portion extending welldown past middle of flattenedseed-bearing part; wingslightly notched at apex, seedsmature in fall of first year.

RangeCommon throughout state,usually found along streambanks, floodplains, and wetupland sites. It may formpure stands or grow inassociation with box elderand red maple.

WoodHeavy, hard, rather strong,brittle, coarse grained; lightbrown, with broad layer oflighter sapwood; commerciallyvaluable and used for thesame purposes as those of thewhite ash; also used exten-sively for ornamentalplantings.

13White Ash(Fraxinus americana)

FormLarge tree; average height 70to 90 feet, diameter 1 to 2 feet,though larger trees can befound. Stout, upright branchesform a narrow crown in theforest, and with sufficientspace, a round-topped orpyramidal head.

BarkGrayish-brown, rather thickon mature trees; narrow ridgesare separated with markedregularities by deep, diamond-shaped fissures.

LeafLength 8 to 10 inches;compound and opposite onstem, consisting of 5 to 9(usually 7) plainly stalked,sharp pointed leaflets; leaflets3 to 5 inches long, smooth torounded tooth along margin;dark green and smooth above,pale green or whitish beneath;leaf scar crescent shaped,extending up sides of new bud.

FruitA samara, length 1 to 11⁄4inches; borne in clusters; seedbearing portion of the fruit isrounded in cross section andwing does not extend along itsside; seeds mature in autumnof first year.

RangeFound over entire state on avariety of sites, but is mostfrequently found on fertile,well-drained sites.

WoodLight brown, close grained,heavy, tough and elastic;preferred to all native woodsfor making tool handles andathletic and sports equipment;also used for agriculturalimplements, furniture interiorfinishes, posts, ties, fuel andfor ornamental purposes.

14 Mountain Ash(Sorbus americana)

FormShrub or small tree; heightsometimes 20 to 30 feet,diameter 4 to 12 inches;spreading, slender branchesform narrow, rounded crown.

BarkAbout 1⁄8 inches thick; smooth,light gray, gradually breakinginto small scales.

LeafCompound; alternatelyarranged on branch; lengthabout 6 to 8 inches, composedof 13 to 17 leaflets; eachleaflet 3 to 4 inches long andabout 1 inch wide at themiddle; leaflets have longpoints with toothed edges,bright green above, turningbright yellow in fall.

FruitA pome; bright orange,occurs in dense clusters;diameter about 1⁄4 inch;has thin layer of sour fleshcontaining 1 to 2 seeds;matures in fall of first season.

RangeFound scattered in woods ofnorthern Wisconsin; bestdevelopment occurs alongedges of lakes and swamps;does best in moist locations,but survives fairly well in drierareas and on thinner soils.

WoodLight, soft and weak; palebrown, with light coloredsapwood; slow growth gives itvery close grain; has nocommercial value, except forornamental purposes.

NotesBerries remain on tree duringthe winter and are relished bybirds for food.

15Bigtooth Aspen,Poplar, or Popple

(Populus grandidentata)

FormMedium to large tree; heightsometimes 60 to 80 feet,diameter 10 to 20 inches;slender rather than rigidbranches form narrow roundedcrown; stem is usually clearof dead branches.

BarkSmooth, gray or yellowish-green; furrowed and darkbrown at base of old trees.

LeafAlternate, coarse-toothed;length 3 to 4 inches; darkgreen upper surface; leavesappear 1 to 2 weeks later thanthat of quaking aspen, and atfirst are silvery white. Budsare light gray, downy, not sosharply pointed and largerthan those of quaking aspen.

FruitMale and female catkins arefound on separate trees. Thefruit is a capsule, 1⁄4 inch long,numerous capsules borne oncatkins 4 to 6 inches long;capsules contain many seeds

surrounded by long whitehairs that are winddisseminated; matures in Mayof the first year. Main mode ofregeneration is by rootsuckering after cutting.

RangeFound over the entire state,but prefers sandy or rich soilsthat are moist.

WoodThe use of aspen has increaseddramatically over the pastdecades which has changed itsstatus from a “weed” tree tothe most highly used species inWisconsin. It is the primaryraw material source for thepulp and paper, hardboard,wafer board and orientedstrand board industries.Other industries use it inthe production of lumber,matchsticks, lath andshavings. The residuegenerated at these industriesis used in the production ofdensified wood fuels (pellets) orburned directly as green fuel.

16 Quaking Aspen(Populus tremuloides)

FormA short-lived, small tomedium sized tree; may reachheight of 60 to 70 feet anddiameter of 12 to 20 inches,but usually somewhatsmaller; slender branchesform an open, round crown;stem of tree is usually free ofdead branches.

BarkThin, white to gray-green,almost smooth with blackareas around base of limbs;has bitter inner bark.

LeafAlternate; small, broadly oval,short-pointed at end andfinely toothed along margin;green and shiny above, dullgreen below; usually ranges insize from 1 to 2 inches. Leafstalks are flattened at rightangles to leaves, causingleaves to quake or tremble ina very slight breeze.

FruitMale and female catkins areon separate trees; fruit is acapsule; 1⁄4 inch long capsulesborne on catkins 4 to 6 incheslong; each capsule containsmany seeds surrounded bylong white hairs that are winddisseminated. Ripens in latespring (May or June) beforefull expansion of leaves.Regeneration is mainly byroot suckering followingcutting of tree.

RangeFound in all parts ofWisconsin; one of first speciesto appear after cutting or fire.Found commonly on cutoverland; grows well on sandy,gravelly soils, but thrivesbetter on good soil.

WoodLight brown, surrounded bythick, nearly white sapwood;light, soft, not strong; usedextensively in manufacturingof pulpwood for books, andmagazine papers, and lowgrade lumber.

17Balm of Gilead orBalsam Poplar(Populus balsamifera)

FormMay attain height of 60 to 80feet and diameter of 11⁄2 to 3feet or more; grows uprightwith narrow open, pyramidalcrown of horizontal branches.

BarkThin, smooth, greenish-brownin color on young trees;thicker, furrowed and gray-black in color on old trees.

LeafAlternate, ovate, long pointed,edges finely toothed, darkgreen and shiny above; paleand often stained by resinblotches beneath. Buds arelarge, pointed and coveredwith a resinous pitch; give offstrong, pungent aroma.

FruitMale and female flowers areon separate trees; the fruit is acapsule, borne in catkins4 to 6 inches long; capsulecontains many seeds coveredwith white hair; winddisseminated for longdistances. Seeds mature in

May or early June.Regeneration usually by rootsuckering following cutting.

RangeNaturally distributedthroughout northern part ofstate, along streams and edgesof swamps or in other coollocalities.

WoodSoft, not very strong, closegrained, heartwood lightbrown, sapwood white; usedfor pulp, boxes, packing casesand rough lumber.

18 Basswood or Linden(Tilia americana)

FormHeight 60 to 80 feet, but oftenexceeding 100 feet with adiameter of 1 to 3 feet; trunkoften continues straight intotop of dense rounded crown.Stump sprouts readily and isoften seen as a group of4 to 5 stems originatingfrom an old stump.

BarkGray with shallow furrowsand vertical, scaly ridges.

LeafAlternate; length and width4 to 6 inches; heart-shaped,margin coarsely toothed,sharp-pointed at tip; atmaturity, thick, shiny greenabove and paler underneath.

FruitRound, hard, nut-like 1⁄4 inchin diameter, containing 1 to 2seeds; covered with short,thick, brownish-red wool,attached in clusters to a leafybract which later acts as awing to disseminate seeds onwind; fruit often hangs on treelong into winter. Flowers arefragrant, and from themchoice-grade honey is madeby bees.

RangeCommon throughout the stateon rich, well-drained loamysoils, in mixture with otherhardwoods.

WoodLight, soft, tough, not durable;light-brown with scarcelydistinguishable sapwood; usedin manufacture of paper pulp,wooden ware, furniture,trunks, crating, drawingboards and lumber.

19Beech(Fagus grandifolia)

FormA tall and slender tree in theforest, with a narrow crown;in the open, with a short,thick trunk and broad,compact, rounded crown.Usually attains heights of 50to 75 feet.

BarkMost distinctive, it maintainsa smooth, steelgray surfacethroughout its life.

LeafSimple, oval leaves 3 to 4inches long, pointed at theapex and coarsely toothed,becoming leathery whenmature. Persist on the tree inthe winter.

FruitA stalked, prickly 4-valvedbur, containing usually 2triangular, shiny brown nutswith a sweet, edible kernel.

RangeFound in eastern Wisconsinon fertile, well-drained soilsderived from limestone. In thevicinity of Racine, it reachesonly a few miles inland fromLake Michigan, but farthernorth it extends as far west asthe Wolf River in LangladeCounty.

WoodHard and strong, but notdurable; is used for chairs,tool handles, lumber andfuelwood. Although beech isnot a highly commercialspecies, it should be retainedwhenever possible for itswildlife value. It is desirablefor landscape work because ofits beauty and freedom frominsect pests.

20 Bluebeech, AmericanHornbeam or Musclewood

(Carpinus caroliniana)

FormSmall tree or shrub; heightrarely 30 feet, spreading,rounded, bushy crown;trunk often short andcharacteristically irregularlyfluted; resembles muscles of aflexed arm.

BarkThin, smooth; light, gray-brown to slate-gray, sometimesmarked with broad, dark-brown horizontal banks.

LeafAlternate; oval, long-pointed,double-toothed along margin;length 2 to 3 inches; veinsprominent in herringbonepattern; pale, blue-green andsmooth above, light yellow-green below.

FruitNutlet about 1⁄3 inch long,attached to a 3-lobed leaf-likebract; bracts are clusteredtogether on a hanging stalk;bract may act as wing inaiding seed distribution bywind; fruit ripens in August.

RangeFound over the entire state,usually on rich moist soils andwell-drained soils in the shadeof other trees.

WoodTough, close-grained, heavy,very hard and strong; lightbrown, with thick whitesapwood. The tree is of nocommercial importance, but inthe past the wood was used forlevers, tool handles, woodedcogs, mallets, wedges and fuel.

NotesAlso known as Water Beech.

21Paper, White orCanoe Birch(Betula papyrifera)

FormHeight 65 to 70 feet, diameter12 to 20 inches; rounded topyramid-shaped crown.

BarkThin, smooth, reddish-brownon young trees turningcreamy white with age;marked by many pores or“lenticels;” readily peeling inlarge pieces exposing orangeinner bark; branch scarsmarked with inverted black V.

LeafAlternate, length 2 to 3inches, width 1 to 2 inches;oval or heart-shaped, pointed,rounded at base, irregularlytoothed; becomes thick andleathery in texture, dark greenon upper side and yellowish-green on lower side.

FruitA catkin, about 1 inch long;contains many tiny, wingedseeds, seeds about 1⁄6 inch inlength; seed matures inAugust and September,

disseminating throughout thefall and may even be seenscattered on the snow.

RangeGenerally abundantthroughout the state andoccurs chiefly on the bettersand and gravel soils inmixture with pine and aspen.

WoodHard, strong, tough, light inweight; brown tinged with redheartwood, nearly whitesapwood; used for spools,toothpicks, toys, handles,paper pulp, flooring, firewoodand interior finish.

NotesYears ago, birch bark wasextensively used by northernNative Americans for canoesand wigwams and for makingbaskets, cups, bags and otheruseful utensils.

22 River or Red Birch(Betula nigra)

FormIn Wisconsin, normally 40 to60 feet in height and 1 to 2feet in diameter; often forkinglow to the ground and forminga broad, spreading crown.

BarkDark brown at base of oldtrunks and deeply furrowed;higher up on main stem andon larger branches, becomeslustrous reddish-brown; peelsfreely in papery layers; thesepersist on tree and give it aragged appearance; twigs arereddish color.

LeafSimple, alternate and doublytoothed; length 2 to 4 inches;usually shallowly andirregularly lobed.

FruitA catkin, 1 to 11⁄2 inches inlength; contains numerouslittle winged seeds; seed ripensin late spring or early summer.

RangeGrows along rich bottomlandsof streams and rivers insouthwestern corner of state,especially in Mississippi andWisconsin River Valleys.

WoodLight brown heartwood withthick, pale sapwood, close-grained, hard, strong; however,since this tree is scattered in itsdistribution and mostlyconfined to banks of streams, itdoes not figure largely forcommercial pulpwood orlumber, but is used to a greatextent for fuel; used some infurniture manufacturing.

23Yellow Birch(Betula lutea)

FormHeight occasionally 85 feet,diameter 2 to 3 feet; developinga broad, round crown.

BarkYellow-gray or straw colored;peeling freely into thin,papery layers on youngertrees, but developing ragged,broken plates on mature trees.Twigs light brown, lustrous,and slightly aromatic with oilof wintergreen.

LeafAlternate; oval to oblong,double-toothed margin;length 3 to 5 inches; dull darkgreen on upper surface andpaler beneath.

FruitCatkin, about 1 inch in length,contains numerous minutewinged seeds when mature.Ripens in fall of first year.

RangeCommon in the northern halfof state on rich, moistuplands with scattered treesas far south as Sheboygan,Sauk and Grant counties.

WoodHeavy, strong, hard, close-grained, light brown withpale sapwood; takes goodpolish; used for flooring,interior finish, veneers,wooden ware, furniture andsmall wooden novelties; anexcellent firewood.

24 Box Elder(Acer negundo)

FormHeight 30 to 50 feet onfavorable soils, diameter mayreach 18 inches; rather bushyon unfavorable soils; limbsand branches fragile; trunkoften dividing near theground, forming anunsymmetrical, open crown.

BarkSmooth and green to purpleon young branches; thin,grayish to light brown anddeeply divided on old trees.

LeafOpposite; compound; 5 to 8inches in length, usually withthree leaflets (rarely 5);lustrous green in color; lengthof leaflets 2 to 4 inches, width1 and 2 inches.

FruitA samara, 2 winged, hangingin clusters, similar to that ofsugar maple, but smaller;ripens in late summer orearly fall; often stays on treesall winter.

RangeCommon throughout thestate; grows naturally alongstreams and in cool ravines;fairly rapid-growing tree,prolific in reproduction.

WoodCreamy white, soft, light andclose-grained; decays rapidlyin contact with heat andmoisture; used occasionallyfor fuel; has no generalcommercial value.

25Butternut orWhite Walnut

(Juglans cinerea)

FormReaches height of 60 to 80 feetand diameter of 3 feet; topdevelops into open, broad,crown; may be distinguishedfrom black walnut by velvetcollars just above scars left bylast year’s leaves.

BarkDivided into broad, scalyintersecting ridges, forming arough diamond-shapedpattern; light gray to lightbrown.

LeafAlternate compound leaves;length 15 to 30 inches, eachwith 11 to 17 sharply pointed,oblong, finely-toothed leafletsabout 2 to 3 inches long;yellowish-green above andhairy underneath. The pith inthe twigs is chambered andchocolate brown.

FruitLight brown nut enclosed inoblong, somewhat pointed,sticky, yellowish-green huskabout 2 inches long; huskcovered with short, rusty,sticky hairs. Nut has rough,grooved shell and oily, sweetedible kernel.

RangeA common occurrence in thesouthern part of the state andis known to extend northwardinto Langlade, Burnett andAshland counties. It grows onthe better sites.

WoodLight, soft, not strong; coarsegrained, light brown; takesgood polish; used for furnitureand interior finish for houses.

NotesButternut canker has killednumerous trees throughoutWisconsin.

26 Black Cherry(Prunus serotina)

FormHeight 50 to 70 feet, diameter 8inches to 2 feet; with a narrowto broadly rounded crown.

BarkSmooth, bright, reddish-brown, marked byconspicuous narrow, whitehorizontal lines on youngtrees; on older trunks, thick,dark brown to nearly black,rough and broken into thickirregular scales.

LeafAlternate; simple, oval, shinyabove, paler below; edgesbroken by many fineincurved teeth. Petioles andsmall branches have bitteralmond taste.

FruitA drupe, borne in long,hanging clusters; dull purplish-black, containing a single seed;is edible but somewhat bitter;ripens in late summer.

RangeDistributed over entire state,but is most common insouthern half on thebetter soils.

WoodReddish-brown with yellowishsapwood, moderately heavy,strong, fine-grained; does notwarp or split in seasoning; hasexceptional luster and color;used for furniture, interiorfurnishing, tools andimplement handles.

27Choke Cherry(Prunus virginiana)

FormA shrub or small tree; heightusually not over 20 to 25 feet,diameter 4 to 8 inches; withan irregular, rounded crown.

BarkThin; on young trees issmooth, shiny, brownish andpeels off easily in thin, film-like layers; becomes thickerdark grayish, with shallowfissures; inner bark has bittercherry flavor and aroma.

LeafAlternate, broadly oval,abruptly and sharply pointed,fine-toothed, bright greenabove, paler underneath;length 3 to 4 inches, width1 to 2 inches.

FruitA drupe, in dense clusters;reddish, turning nearly blackwhen fully ripe; each berrycontaining a single seed, skinof fruit thick; flesh thin anddark; very astringent to thetaste, but edible.

RangeCommon throughout statealong streams, open woods,cut-over and brushy areas.

WoodHeavy, hard, not very strong;of no commercial value inWisconsin.

NotesPopular tree for birds. Mostwidely distributed tree inNorth America, extendingfrom the Arctic Circle toMexico and from the Atlanticto the Rockies.

28 Pin Cherry(Prunus pennsylvanica)

FormShrub or medium-sized tree;20 to 30 feet in height;bearing rather ascendingbranches which form anarrow, rounded crown.

BarkThin, reddish-brown, breakinginto papery layers; marked bylarge, irregular horizontalbands of orange lenticels.

LeafAlternate; length 3 to 4inches; width about 1 inch;oblong; apex pointed; finelyincurved teeth along edge;shiny green when fully grown.

FruitA drupe, about 1⁄4 inch indiameter; thick, reddish skin;thin sour flesh surroundingoblong seed, fruit borne onlong-stalked clusters; ripens inmiddle or late summer.

RangeDistributed over the entirestate, but is most common inthe northern half on areas ofprevious forest fires, cutovers,old fields and roadsides.

WoodLight, soft, brownish withyellowish sapwood; has nospecial commercial value; treeis hardy; provides homes andfeeding grounds for song birds.

29

FormHeight may reach 70 to 90feet, diameter 3 to 5 feet;grows rapidly; long,pyramidal, open crown.

BarkThin, smooth and light grayon young trees; dark gray anddeeply furrowed into broad,rounded ridges on older trees.

LeafAlternate; broadly ovate ortriangular, tapered tip, squareat base; toothed or wavy onedges, 3 to 5 inches acrosseach way; leafstalks flattenedand 2 to 3 inches long; winterbuds covered with chestnut-brown, resinous scales.

FruitCapsule borne on catkins 6 to8 inches long; capsule containsmany seeds that are enclosedin clusters of white cottonyhairs; wind can carry them forlong distances. Can be easilypropagated from cuttings.

Eastern Cottonwood(Populus deltoides)

RangeThroughout Wisconsin,though rarer in the north;often forming extensivegroves along waterways; willgrow on dry locations butmakes most rapid growth onmoist sites.

WoodSoft, light-weight with darkbrown heartwood and thick,nearly white sapwood, warpseasily when drying and rotsreadily; used for boxes,fencing, fuel, rough lumberfor inside use, making high-grade magazine paper forprinting half-toneillustrations; grownextensively for windbreaksowing to rapid growth andadaptability to soil.

30 American Elm(Ulmus americana)

FormLarge tree; height 80 to 90 feet;diameter 2 to 4 feet; main stemoften branches into severallarge branches forming acrown with pendulousbranches; crown vase-shapedand broadly rounded.

BarkThick, divided into irregular,broad, flat ridges; ash-gray tograyish brown.

LeafAlternate; length 4 to 6inches; rather thick,somewhat one-sided; doublytoothed on margin, generallyrough above, smooth below,veins very pronounced andrun in parallel lines from mid-rib to edge of leaf.

FruitA samara; winged, lightgreen, oval and wafer-like inappearance; seed portion incenter surrounded entirely bywings; outer end of each wingdeeply notched; seeds hang inclusters; ripen in spring;widely scattered by wind.

RangeFairly common throughoutstate; found on rich bottom-lands and low, moist hillsthroughout the state inmixture with other hardwoods.

WoodLight brown, heavy, hard,strong, rough and difficult tosplit; used for furniture andveneer for baskets and crates.

NotesVery susceptible to Dutch elmdisease; a few resistanthybrids have been developed.

31Rock Elm(Ulmus thomasii)

FormHeight 80 to 100 feet,diameter 2 to 4 feet; seldomforks like other elms, butretains a straight centraltrunk; forming a narrow,rounded crown with long,graceful branches.

BarkAbout 1 inch thick, ash-gray;divided by deep, irregularfissures into broad, flat ridges;corky ridges or wings developon the bark of the twigs.

LeafAlternate; double-toothedmargin; resembles those of theAmerican elm, but are moreregular in shape, smaller,smoother on both sides, andmore leathery.

FruitA samara, length 1⁄2 inch,ovate, flattened; contains oneseed; slightly notched at outerend; ripens in early summer.

RangeThe rock elm reaches its bestdevelopment in Wisconsin onthe well-drained soils ofLanglade and Shawanocounties, but it is foundsouthward and westwardthroughout the state on avariety of soils.

WoodClose-grained, compact andstrong; light reddish-brownwith thick, light-coloredsapwood; used for agricultureimplements, sills, ties, hockeysticks and furniture.

NotesSusceptible to Dutch elmdisease.

32 Slippery Elm or Red Elm(Ulmus rubra)

FormHeight 50 to 70 feet, diameter16 to 24 inches; main branchesfrequently extend at rightangles to trunk to form broad,open, flat-topped crown.

BarkFrequently 1 inch thick, darkgreenish-brown; broken byshallow fissures into flatridges. Winter buds coveredby brown, silky hairs.

LeafAlternate; 4 to 6 inches inlength; ovate, sharp-pointed,base not symmetrical, doubletoothed on margin; thick,dark green and rough on bothsides; turns to yellowish colorbefore falling.

FruitA samara; seed surroundedby thin, broad, greenishwing; diameter about 1⁄2 inch;ripens when leaves are abouthalf grown.

RangeDistributed over the entirestate, but is rare in thenorthern portion and isusually found on banks ofstreams and fertile hillsides.

WoodDark brown with light-coloredsapwood; close-grained,rough, strong, heavy, hard,moderately durable; used forfence posts, ties andagricultural implements;inner bark of trunk andbranches once used to someextent for medicinal purposes.

NotesSusceptible to Dutch elmdisease. Inner bark is fragrant,and when chewed becomesmucilaginous and slippery,whence the tree gets its name.

33Hackberry(Celtis occidentalis)

FormHeight 50 to 75 feet, diameter1 to 2 feet; limbs often crookedand angular; tree-head madeup of slender, pendantbranches or short, bristly,stubby twigs when growing inthe forest; in the open, crownis generally symmetrical.

BarkGrayish-brown, muchroughened with prominent,short, corky ridges.

LeafAlternate; length 2 to 4inches; ovate and sharplytoothed toward end of leaf;oblique at base; prominentveins; hairy on upper side.

FruitBerry-like drupe, 1⁄4 to 1⁄3inches in diameter; thin,purplish skin; sweet yellowishflesh, sometimes called sugarberry; ripens in September;frequently hangs on tree mostof winter.

RangeFound sparingly in southernand western part of the state,extending northward throughthe Wisconsin River Valley toMarathon County and up toSt. Croix and Polk County,most abundant on richalluvial soil, but will grow onvarious types of soil.

WoodHeavy, rather soft, weak andcoarse-grained; light yellow orgreenish-brown with narrowwhite sapwood; used inmanufacture of furniture,fuel and only occasionallyfor lumber.

34 Bitternut Hickory(Carya cordiformis)

FormHeight 50 to 75 feet, diameter1 to 2 inches; the crown isopen and rounded at the top.

BarkGranite-gray, faintly tingedwith yellow; broken into thin,plate-like scales; not as roughas most hickories; bark doesnot strip off as that ofshagbark hickory. Winterbuds are compressed, scurfyand bright yellow, 1⁄2 inch ormore in length.

LeafAlternate; compound; length6 to 10 inches; composed of 7to 9 leaflets, 4 to 6 inches longand with toothed margins;each leaflet relatively muchsmaller and more slenderthan that of other hickories.

FruitNut usually thin shelled,smooth, brittle; length about1 inch with thin husk thatusually splits only partly downside. Nut is broader than long;kernel is very bitter.

RangeFound on well-drained, fertilesoils in the southern part ofthe state extending northwardto Langlade, Rusk and Polkcounties.

WoodHard, strong, heavy, andreddish-brown; used forhoops, fuel and farmimplements. Wood isconsidered somewhat inferiorto the shagbark hickory.

35Shagbark Hickory(Carya ovata)

FormA large tree; height 60 to 100feet, diameter 1 to 2 feet;open, rounded crown withconspicuous shaggy bark.

BarkRougher than that of otherhickories; shaggy, light grayand separates into thick,vertical strips that are onlyslightly attached to tree.Terminal winter buds arelarge, hairy and egg-shaped.

LeafAlternate; compound; length8 to 15 inches and composedof 5 (rarely 7) ovate leaflets;end leaflet larger than otherleaflets; margin of leafletcovered with fine teeth andnumerous hairs.

FruitA nut borne singly or in pairs,globular in shape, enclosed inhusk that is thick and deeplygrooved at seams and splitsentirely into 4 parts. Nutscompressed or flattened andlight-brown colored; shell isthin and kernel is sweet.

RangeFound in the southern part ofthe state on moist, rich soilsand well-drained hillsides.

WoodLight brown heartwood withnearly white sapwood; heavy,hard, tough and very strong;used largely in manufacture ofagricultural implements andtool handles; makes very goodfuel and is best of all woodsfor smoking meats. Nut isimportant wildlife food source.

36 Ironwood orHop Hornbeam

(Ostrya virginiana)

FormHeight 20 to 40 feet; diameter5 to 12 inches; broad, roundedcrown; branches long andslender, drooping at ends.

BarkAbout 1⁄4 inch thick; lightgray-brown; finely dividedinto narrow, thin scales thatare easily rubbed off.

LeafAlternate; generally oblongwith narrow tips, doublytoothed along margins; length2 to 4 inches; dark, dull,yellow-green above and lightyellow-green below.

FruitIn clusters of leafy bracts;each bract contains oneflattened, ribbed, hard nutletabout 1⁄3 inch long and 1⁄8inch wide; fruit ripens in Julyand August.

RangeFound throughout the state,usually on the better, well-drained soils or gravel ridgesin mixtures with otherhardwoods.

WoodVery strong, hard, heavy,durable, light brown, withthick, pale sapwood; used forfence posts, handles of tools,mallets and other smallarticles and fuel.

NotesThe tree receives its commonname from the quality of itswood and its hop-like fruit.

37Juneberry or Serviceberry(Amelanchier canadensis)

FormA small tree; height seldomover 25 feet, diameter 4 to 8inches; rather narrow,rounded crown.

BarkThin, usually gray; smooth onbranches and upper part ofstem, breaking into shallowfissures on short trunk.

LeafAlternate; 3 to 4 inches long,ovate, apex sharply pointed,fine-toothed; purplish-brownuntil nearly mature; lightgreen covered with scattered,silky hairs when mature.

FruitA pome; sweet, edible, round,dark purple when ripe;diameter 1⁄3 to 1⁄2 inches; fruitripens in July or August.

RangeCommon throughout state,but best development is alongbanks of streams, shores oflakes, or open upland woods.

WoodHeavy, hard, strong, close-grained, dark brown; has nocommercial importance;desirable as ornamentalbecause of flowers and forhabitat and food for wildlife.

38 Black Locust(Robinia pseudoacacia)

FormA medium sized tree, 30 to 50feet high; sometimes larger.Open grown specimens usuallybranch low, forming a narrow,open crown. Twigs andbranchlets carry strong, sharpspines which occur in pairswith a leaf-scar between them.

BarkBrown with yellow or orangeinner bark; heavily furrowed,forming an interlacing patternof fibrous ridges, rope-like.

LeafAlternate, compound;consisting of from 7 to 19oblong, thin leaflets.

FruitA legume; 3 to 5 inch longpod containing 4 to 8 small,hard seeds which ripen late inthe fall and persist throughthe winter on the tree.

RangeNot native to the state, buthas been planted extensively.In some places has escapedfrom cultivation, as it growson a wide variety of soils.

WoodYellow in color, close grained,very heavy and hard; strongand very durable in contactwith the soil. The wood ispotentially valuable, butrarely obtains log size due toattacks of the locust borer. Useis therefore limited to fenceposts and firewood.

NotesOriginally planted for soilerosion control purposes, forwhich it is well suited.Fragrant, white flowers in thespring make it very attractive.Is generally considered a weedbecause it spreads prolificallyby suckering.

39Honey Locust(Gleditsia triacanthos)

FormHeight 30 to 50 feet, tallerunder very favorable condi-tions; may reach diameter of16 inches; slender, spreading,somewhat pendulous branchesform broad, open, rather flattop crown.

BarkDark gray or brown on oldtrees; dividing into strips;strong, sharp, shiny branchedthorns appear on one-year oldbranches and remain formany years.

Leaf2 types, both alternate; type 1is compound with 18 to 28leaflets; type 2 is doublycompound, consisting of 4 to7 leaflets, each 6 to 8 incheslong; each leaflet consisting of16 to 24 secondary leaflets.

FruitA legume; length 10 to 18inches, width 1⁄2 to 11⁄2 inches;flat, dark brown or blackwhen ripe, containing seedsand yellow-whitish pulp; pod

often becomes twisted as seedsripen; seeds are hard and eachis separated from the othersby the pulp.

RangeNative only to southwesternWisconsin, but has beenplanted in other sections. Itattains its best developmenton rich, moist river bottoms,but will do well on fertile,well-drained soil.

WoodReddish-brown heartwood,coarse-grained; hard, strong,not durable in contact withground; used for fence posts,cross ties and fuel; has beenplanted to some extent forwindbreaks and hedges.

NotesA thornless variety of honeylocust is widely planted as anornamental.

40 Red Maple(Acer rubrum)

FormHeight 40 to 65 feet, diameter10 inches to 2 feet, sometimeslarger; forms a narrow,rounded crown.

BarkSmooth, light gray on youngstems; dark gray and rough onold limbs and trunk; old barkdivided by shallow fissures intoflat, scaly ridges at surface,making tree look shaggy.

LeafOpposite; 2 to 5 inches long,3 to 5 lobes, with double-toothed margins; uppersurface light green whenmature; lower surface whitishand partly covered with paledown. Winter buds are small,red and somewhat rounded.

FruitA samara, 2 winged; 1⁄2 to 1inches in length on long,drooping stems; red, reddish-brown or yellow; ripens in latespring and germinatesimmediately.

RangeOccurs over the entire state;prefers moist soils, though iscommon on drier sites inmixture with other trees.

WoodHeavy, close-grained, ratherweak, light-brown; used infurniture manufacturing,woodenware and fuel.

NotesShape and beautiful foliagecolors make red maple animportant ornamental tree.

41Silver Maple(Acer saccharinum)

FormHeight up to 100 feet,diameter 3 feet or more; trunkusually short, divided into anumber of long ascendinglimbs which are againdivided; their small branchesdroop, but turn upward attips, forming large, spreadinground crowns.

BarkOn young trees or branches,smooth and varies in colorfrom reddish to a yellowish-gray; on old branches, darkgray and broken into longflakes or scales.

LeafOpposite; 3 to 5 lobes endingin long points separated bydeep, angular openings;margins toothed; pale greenon upper surface and silveryunderneath; buds roundedand red or reddish-brown.

FruitA pair of winged samaras;wings 1 to 2 inches long;samaras on slender, flexible,thread-like stems about 1 inchlong. Mature in spring, andgerminate immediately.

RangeCommon tree on river bottomsor other deep, moist soils inthe southern 2⁄3 of the state.

WoodLight-brown, strong, fairlyhard, even texture, ratherbrittle, easily worked; decaysreadily when exposed toweather or soil; occasionallyused for flooring, furnitureand fuel; often mixedwith red maple forcommercial purposes.

NotesPopular as a shade tree, butbranches are apt to be brokenin storms.

42 Sugar Maple(Acer saccharum)

FormHeight 80 to 100 feet or more,diameter 2 to 3 feet; sym-metrical, heavy, round crown.

BarkOn young trees, light gray tobrown and somewhatsmooth; on older trees, grayto almost black with long,irregular plates or scaleswhich often loosen on thesides. Twigs are smooth andreddish-brown with sharp-pointed winter buds.

LeafOpposite; 3 to 5 inches long,usually 5 lobed; lobes wavytoothed; dark green on uppersurface, paler green below; inautumn, turning brilliantshades of yellow, orangeand red.

FruitA pair of fused samaras, about1 inch long; matures in fall.

RangeFound throughout the state onthe better soils.

WoodLight brown, hard, heavy,strong, close-grained; knowncommercially as hard or rockmaple; used in the manufac-ture of flooring, furniture,maple syrup and fuel.

43Black Oak(Quercus velutina)

FormHeight 50 to 75 feet,diameter 1 to 3 feet; cleartrunk for 20 feet or more onlarge trees; crown wide andirregularly shaped.

BarkOn young trees, smooth anddark brown; thick and blackon older trees, with deepfurrows and rough, brokenridges; inner bark brightyellow and bitter due topresence of tannic acid.

LeafAlternate; length 5 to 8inches; width 3 to 5 inches;lobed half-way to mid-rib;ends are bristle-tipped; whenmature, thick, dark green andshiny on upper surface, paleon lower; covered more or lesswith down; conspicuous rustybrown hairs in forks of veins.

FruitLight brown acorn thatmatures the second season;length 1⁄2 inch to 1 inch; shapesomewhat round; 1⁄2 to 3⁄4 ofnut enclosed in thin, darkbrown, scaly cup; kernelyellow and extremely bitter.

RangeFound on dry uplands, gravelslopes and ridges oversouthern half of the state.

WoodHard, heavy, strong, coarse-grained, not tough, checkseasily; bright reddish-brownheartwood with thin outeredge of paler sapwood;principally used forconstruction, interior finish,furniture, pulp, ties, fuel;tannin and yellow dye can bemade from bark.

NotesSusceptible to oak wilt.

44 Bur Oak(Quercus macrocarpa)

FormHeight 80 feet or more underfavorable conditions, diameter3 to 4 feet; under unfavorableconditions, not over 25 feet inheight; often grows in theopen where the tree usuallyhas broad top of heavyspreading branches andrelatively short trunk.

BarkThick, deeply furrowed onsurface into irregular, plate-like broken scales; dark grayto black in color. Bark onsmaller branches developscorky wings, or ridges, givingit a gnarly appearance.

LeafLength 6 to 10 inches, width 3to 6 inches; crowded at ends oftwigs; resembles white oak,but has pair of deepindentations near base andwavy notches on broadmiddle and upper portions;dark green above, paler andhairy beneath.

FruitAcorn set deeply or almostenclosed in fringed, burr-likecap, ovoid in shape; diametermay reach 1 inch or more;however, varies widely inrespect to size and degree towhich nut is enclosed in themossy fringed cup. Seed isbitter, and matures in 1 season.

RangeDistributed over the entirestate; towards the north, treesare smaller; prefers moist,well-drained soils; thecommon oak of the “oakopenings” in the southwesternpart of the state.

WoodHeavy, hard, strong, tough,durable, rich brownheartwood; uses similar tothat of white oak.

45Chinkapin Oak(Quercus muehlenbergii)

FormReaches 80 to 100 feet inheight and 3 to 4 feetin diameter.

BarkRarely 1⁄2 inch thick andbroken into thin, loose, palegray scales.

LeafUsually crowded on the end ofthe slender branches, 4 to 7inches long; margin withsharp, incurving or broadround teeth. Upper surface islight yellow-green, theunderside pale and coveredwith fine short hairs.

FruitThe acorns grow singly or inpairs, with short heavy stalks,the nut covered for half itslength by the thin cup. Seed issweet and edible.

RangeDistributed sparsely oversouthern Wisconsin, extendingup to the Rock River aboveJanesville, up the Wisconsin toSauk City and up the Missis-sippi to Lynxville. Reportsshow that it occurs as far eastas southeastern WaukeshaCounty. It grows on limestoneridges, and on fertile bottomlands and rocky stream banks.This tree was once fairlyplentiful in several southwest-ern counties and should befavored where found.

WoodThe wood is similar to whiteoak and equal to it in quality,although it tends to containmore knots.

46 Northern Pin, Hillsor Jack Oak

(Quercus ellipsoidalis)

FormIn Wisconsin, Northern pinoak seldom exceeds a heightof 50 feet or a diameter of2 feet. The trunk is short andbears many forked branches.

BarkThe bark resembles that of thescarlet oak, but the inner barkis pale yellow.

LeafThe leaves are similar toscarlet oak, but not so shinyabove, with five to seven lobes.Late in autumn, they turnyellow or pale brown, or moreor less blotched with purple.

FruitThe acorn requires 2 seasonsto mature, and is enclosed for1⁄3 to 1⁄2 of its length in thecap, which gradually tapersat the base.

RangeNorthern pin oak is foundthroughout the state, usuallyon sandy soils of low fertility.It originally grew in mixturewith pines, but fires havekilled most of the pines, whilethe oak was able to reproducefrom sprouts. As a result, thereare many acres in Wisconsincapable of producing pinethat are growing this oak.

WoodThe wood resembles red oakand is used for fuel, posts,railroad ties and somehardwood pulp.

47Red Oak(Quercus rubra)

FormHeight 70 to 90 feet; diameterranges from 2 to 3 feet; inforest situations, tall andstraight with clear trunk andnarrow crown.

BarkOn young stems, smooth, darkgray to dark brown; on oldertrees, thick and gray to brown;broken by shallow fissures intoregular, flat, smooth-surfaced,vertical plates.

LeafAlternate; length 5 to 9 inches;width 4 to 6 inches, broadertoward the tip; divided into 7to 9 lobes, each extending 1⁄2way to the mid-rib; each lobesomewhat coarsely toothedand bristle-tipped, dull greenabove, paler below. Buds thickand pointed.

FruitLarge, bitter acorn, maturingthe second year; length 1 to11⁄2 inches; blunt-topped, flatat base, enclosed in a veryshallow, dark brown cup thatis velvety inside.

RangeGrows throughout Wisconsinon the better sites.

WoodLight, reddish-brownheartwood; hard, strong andcoarse; used for constructionand finish of houses, furnitureand fuel. Best logs are largelycut into veneer.

48 Swamp White Oak(Quercus bicolor)

FormHeight may reach 65 to 80feet and diameters of 2 to 3feet; forming an open,sometimes irregular, round-topped crown.

BarkThick, deeply and irregularlydivided by fissures into broadridges; grayish-brown; bark onupper branches ragged andoften peeling.

LeafLength 5 to 6 inches, width 2to 4 inches; often crowdedtowards ends of twigs; broadat middle (pear-shaped) andwedge-shaped at base; wavyand indented along margin;dark green and shiny above,grayish and fuzzy beneath.

FruitAn acorn; length about 1 inch;width 3⁄4 inches, enclosed forabout 1⁄3 of its length in thick-walled cup. Usually in pairson slender, dark brown stalkswhich are 2 to 4 inches long.Mature in 1 season.

RangeSparsely distributed over thesouthern part of the state,extending into Wood andBuffalo counties; it grows onthe borders of streams andswamps in moist, fertile soil.

WoodLight brown, hard, strong,tough and durable;commercially, its uses andproperties are similar to whiteoak and bur oak.

49White Oak(Quercus alba)

FormHeight 60 to 100 feet,diameter 2 to 3 feet and maybecome large. Tall andstraight in forest; short in theopen with wide spreading,broad, rounded crown;numerous heavy limbsspreading irregularly.

BarkPale gray, scaly, but notdeeply fissured.

LeafAlternate; length 5 to 9 inchesand about half as broad;crowded towards ends oftwigs; deeply divided into 5 to9 lobes; becoming light greenabove and much paler below;sometimes remain on treemost of the winter.

FruitA light brown acorn maturingthe first year; length 3⁄4 to 1inch, about 1⁄4 enclosed incap; germinates in a fewweeks after ripening andsends down a long, deep toproot before winter.

RangeCommon on the better soils inthe southern half of the state.

WoodLight brown; hard anddurable; one of our most usefulwoods for heavy construction;used for railroad ties, interiorfinishes, furniture and fuel.

50 Wild Plum(Prunus americana)

FormShrub or small tree; heightusually 15 to 25 feet;maximum diameter 10inches; trunk usually shortand thorny; divides a shortdistance from the ground.

BarkThin, reddish-brown; brokeninto thin plates.

LeafAlternate; somewhat oval,long and narrow-pointed;double-toothed along edge;dark green above, palerbelow; length 2 to 5 inches,width about 2 inches.

FruitA drupe; 3⁄4 inch in diameter;outer skin orange-red whenripe, with yellowish, sweetflesh; flesh clings to seed; fruitripens in late summer, andcontains a single stone.

RangeFound generally scattered overthe state in thickets,particularly along banks ofstreams; grows best on richsoil or in moist locations,though will grow elsewhere.Its hardiness also fits it forrather severe locations.

WoodStrong, hard, close-grained;dark brown with light-coloredsapwood; tree has no specialcommercial value other thanfor its fruit and wildlife value.

51Black Walnut(Juglans nigra)

FormHeight often 100 feet,diameter 2 to 4 feet; whengrown in the open, stem short,crown broad and spreading.

BarkThick and very dark brown;divided by rather deep fissuresinto round ridges. Blockyappearance.

LeafAlternate on stem; compound,1 to 2 feet long, consisting of 7to 11 pairs of yellow-greenleaflets, smooth above, paleand hairy underneath; leafletsabout 3 inches long, extremelytapered at ends and toothedalong margin. The chamberedpith is cream colored.

FruitA large, round nut bornesingly or in pairs and enclosedin solid green husk, which isnot sticky and does not spreadopen even after nut is ripe.The nut is black with veryhard, thick, finely-ridgedshell, enclosing a rich, oily

kernel which is edible andhighly nutritious; matures infall of first season.

RangeGrows on rich bottomlandsand moist, fertile hillsides insouthern part of state; is easilypropagated from nuts andgrows rapidly on good sites.

WoodMost valuable forest tree inthe state. Rich chocolate-brown heartwood is ofsuperior quality and value;heavy, hard, strong, andcomparatively free fromwarping and checking; takesa high polish and is verydurable; highly prized for agreat variety of uses such asfurniture and gun-stocks;small trees consist mostly ofsapwood, which is light-colored and not durable.

52 Willows(Salix spp.)

FormA large genus of trees andshrubs, some varieties notcommonly distinguished fromeach other; become large whengrowing along streams andother moist places; scraggly,dwarfed shrubs when growingin drier, less favorable sites.The black willow is native, andthe weeping and crack willowswere originally foreign, orexotic. On favorable sites,some trees are often 35 to 50feet high, with a diameter of 6to 25 inches. The black willowmay be 30 to 40 feet high,though it could also be ashrub; usually short trunk,stout, spreading branches, anda broad, rather irregular, opencrown. The peach-leaf willowis somewhat greenish-yellow;twigs somewhat drooping.

BarkDark brown to gray on largetrees; thick, rough, furrowedand flaky.

LeafWhite willow and crack willowleaves: whitish on lowersurface; crack willow: large,saw-toothed leaves and twigsthat crack or break frombranches very easily; whitewillow: leaves smaller, finelytoothed, and oftenpermanently silky; black

willow: very narrow leaves,green on both sides; peach-leaf willow: long pointed,lance-shaped leaves, whitishunderneath, borne on long,slender, somewhat twistedstems; weeping willow: leaveswhitened or pale beneath.

FruitFlowers in dense, elongatedclusters know as “catkins”;flowers usually appear withleaves in spring. Willows maybe propagated with “cuttings”more easily than with seeds.Seeds are minute, maturing inlate spring or early summer.

RangeMany varieties occur over awide range in Wisconsin andthe United States from moistconditions to dry uplandprairies. Many European andornamental varieties havebeen introduced.

WoodLight brown, soft, weak,flexible, coarse-grained; thin,whitish sapwood; used forfuel, erosion control,ornamental planting,windbreaks and charcoal.

53Sign Posts to Followin Using your

“Tree Road Map”

Deciduous(Hardwoods)

Coniferous(Evergreen)

AlternateBranching

OppositeBranching

Pith of TwigChambered

Pith of TwigNot Chambered

54

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55

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56Sign Posts to Follow

in Using Your“Tree Road Map”

Simple leaf not lobbedwith toothed outline

Simple leaf lobbed withsmooth outline

Compound leafwith 13 leaflets

Single needles

Needles in groups Needles in clusters

57

The forest fire hazard inWisconsin is extremely highcompared to other states. Thisis due to our geographiclocation, soil and timbertypes, topography, andgeneral climate, all of whichcombine to create conditionsunder which fires start easilyand spread rapidly. This istrue particularly in the vasttimber regions of the state.

Adequate fire protection is thebasis of all conservation. If weare to preserve our forests –which means if we are tocontinue to enjoy hunting,fishing, camping, and thebeauties of the out-of-doors aswell as the economicadvantages of forest productindustries – we must all do ourpart in preventing forest fires.

Actually, fire preventionrequires only a little goodjudgment. Campfires shouldbe built on mineral soil withall leaves and duff clearedback for a 5-foot radius. Allfires should be attended whilethey are burning. Before

How to PreventForest Fires

leaving the fire, enough watershould be poured on it to kill itcompletely. It is a good policyto feel the ashes with the handto make sure they are dead.Never bury a campfire withduff or litter since this onlyholds the fire, allowing it tosmolder in readiness to startup later. Never throw awayburning cigarettes and cigarstubs, pipe ashes, or matchesin the woods.

You Violate a ForestLaw if You1. Fail to extinguish your fire.

2. Burn without a permit.

3. Allow a fire to spread.

4. Cut timber withoutpermission of the owner.

5. Remove forest productsfrom the lands of anotherwithout written permissionof the owner.

The destruction, injury, ordefacing of any sign, guidepost, building or property ofany kind belonging to thestate is unlawful.

58

Most people can tellreasonably well how dry it isby observing some naturalsigns that are present. Thatwas once the way the firefighters determined forest firedanger – but no more.

Now the fire managers usesuch factors as relativehumidity, fuel moisture,precipitation, wind velocity,and condition of groundvegetation – dry, green, or inbetween these two. Tempera-ture also has a relative effect.The ranger can tell from hiscalculation what he has toprepare for in the way ofpeople and equipment to copewith the current fire situation.

Information on the currentforest fire danger in forest andwildland areas is often givenon radio and TV programs.

The sign found at manyranger stations throughoutthe state, displays the currentlocal fire danger rating. Therating shown on the signrefers to the following burningcondition list and will helpyou to understand what thesituation is where you live.

ExtremeExplosive conditions. Firesstart easily, burn fiercely andcrown readily. Often verydifficult or impossible tocontrol during the day.Burning not recommended.

Very HighVery dangerous conditions.Fires start easily, spread veryrapidly, crown and spot. Very

difficult to control. Burning isnot recommended.

HighDangerous conditions. Firesstart readily from a match orsparks, spread quickly, andspot readily. Difficult tocontrol. Burning is notrecommended.

ModerateFires start from a match orburning embers, spreadquickly in dry grass or leaves.Burn with extreme caution.

LowFires will start from an openflame, spread slowly and inabsence of wind tend to goout. The safest time to burn.

How Forest FireDanger is Measured

59

Most fires are caused bypeople. There are so manypeople using Wisconsin forestand recreational areas todaythat it is very difficult to reachall of them with a fireprevention warning. Themass of outdoor enthusiastskeeps changing from day today. This makes the fireprevention problem evenmore complex. No one reallyintends to destroy the beautyof our forests or damage ournatural resources, but it isdifficult for persons notacquainted with fire controlwork to realize the tremen-dous, destructive potential ofwild, uncontrolled fire.

You can help prevent forestfires by being extra carefulwhen you are hunting,camping, hiking or otherwiseenjoying the outdoors.

Useful FireWisconsin’s Forest Fire Controlprogram is not intended toprohibit the proper andbeneficial use of fire. Fireadequately controlled andmanaged can be an efficientand effective land manage-ment tool, as it is for heating,cooking, recreation, orindustrial use. It should alwaysbe recognized that uncon-trolled fire is a devastatingnatural force. In recognition ofthis and other factors such asair pollution and conditions ofextreme danger, the best skilland judgment should be usedto minimize risks andenvironmental damage.Alternative procedures shouldbe used when practicable.

What Causes ForestFires to Start?

60 Wildlife and Forests

The abundance and diversityof Wisconsin’s wildlife wouldbe greatly reduced without thepresence of the forest treesdescribed within thispublication. They provideshelter, nest and den sites, aswell as, a source for food.However, not only does thepresence or absence of forestaffect wildlife, but the forestsize, age and composition hasa big impact.

SizeAs the size of a forestincreases, so does the varietyof wildlife species present. Birdspecies such as the barred owl,yellow-bellied sapsucker orhermit thrush are found mostfrequently in forests 100 acresin size or larger.

AgeA young forest may be morefavorable than an older forestto some species. A 1969-82study of ruffed grouse incentral Wisconsin found thatthe density of grouse more

than doubled when theproportion of the aspen-oakforest under 25-years oldincreased from 13% to 55%.

CompositionThe mix of tree species foundin a forest will also influencewildlife. A forest without oaktrees is likely to be withoutsquirrels and not used muchby wild turkeys. A lack of deadtrees or snags will reducewoodpecker use. As you learnto recognize Wisconsin’s trees,you will be opening the doorto life-long study andappreciation of wildlife andforest relationships. You’lllearn that if you care aboutwildlife that you need to careabout the condition of ourforest trees.