Wood — Forest Service Colors and Kinds Agriculture Handbook Number 101 CONTENTS

United States Department of Agriculture Wood — Forest Service Colors and Kinds Agriculture Handbook Number 101 CONTENTS

October 1956 Approved for reprinting August 1981

For sale by the Superintendent of Documents. U.S. Government Printing Office Washington, D.C. 20402 WOOD—COLORS AND KINDS

Prepared by Forest Products Laboratory, Forest Service

A key element in any business transaction in- characteristics. Beginning at the top of the volving wood is the proper identification of species. illustration, end-grained, edge-grained (quarter- Literally scores of different woods are bought and sawed), and flat-grained (plainsawed) surfaces are sold daily for hundreds of uses. A New England all displayed. This is done because certain home may be framed with Douglas-fir from Ore- identifying characteristics show up best on each gon, floored with red oak from Arkansas, sided surface. The terms “edge-grained” and “flat- with California redwood, and trimmed inside with grained” are used in reference to softwood lumber, Michigan yellow birch. Its furniture may be while quartersawed and plainsawed refer to hard- veneered with Pennsylvania black cherry over wood lumber. Wisconsin basswood and fitted with drawers of The manner in which it is sawed from the log will, Indiana sycamore and backs of Carolina sweetgum. of course, determine whether a piece of wood shows It is apparent that familiarity with only locally flat-grained or edge-grained patterns of annual grown species is not enough in today’s lumber growth rings on its wide surfaces. Lumber is markets. manufactured in both forms. Often, any one of several species is suitable for a Each color plate presents two species. Where specific use. Other species, however, may be en- possible, closely similar species are shown together tirely unfit for that use. Of those suitable, some on one plate, so that distinguishing characteristics are better than others because they are stronger, can be more conveniently examined. In other perhaps, or more attractive, or hold paint better. cases, species are paired on one plate because they Others may be superior because they are harder, are often marketed in mixture or used inter- shrink less, resist decay, or are more easily cut and changeably. joined. It follows, then, that correct identification Certain species are not distinguishable from is essential to insure selecting the right wood for a close relatives by the wood alone, even under the given job. microscope. Thus, for example, the wood of many As the official wood identification agency of the different species of red oak is identical in structure United States Government, the Forest Products and appearance even though the trees from which Laboratory annually receives thousands of re- it comes may differ markedly in leaf, bark, and quests for identification service from industry, fruit. From the wood user’s standpoint’, however, other branches of the Federal Government, units botanical differences in trees usually do not matter of State and local governments, and the general so long as their wood is consistent in properties public. This service is requested in connection and appearance. Where appropriate in the de- with business transactions, civil lawsuits, criminal scriptions, differences are mentioned that distin- cases, building codes for homes and other struc- guish a species from closely similar ones not tures, industrial standards, and Government pur- shown. The general range of growth, properties, chase specifications. The Laboratory has also and common uses of each species are also given. been called upon to identify wood from tombs of Obviously, many other species could have been Egyptian Pharaohs, sunken pirate ships, pre- included with the 18 hardwoods and 14 softwoods historic forests, and the beam that supports the described in this publication. Those chosen are Liberty Bell. the species most commonly found in retail lumber In the great majority of day-to-day transac- markets. tions, however, wood identification is a relatively To assist the reader in getting the utmost help simple problem. By acquiring a little know-how, from this booklet, the terms used in the descrip- many lumbermen, dealers, builders, manufactur- tions are defined in a glossary. These terms are in ers, consumers, students, and home-workshop hob- common use among wood technologists, and the byists could solve their identification problems on features of wood to which they apply are regularly the spot. Consequently, this publication was pre- used for identification and other purposes at the pared as an aid to those persons concerned with Forest Products Laboratory. The common and identifying the more common native species of botanical names of species conform to the official wood. Forest Service nomenclature for trees. Cubic- Characteristics that are apparent to the naked foot weights of species described are averages eye and that distinguish our native woods from taken at 12 percent moisture content; specific each other are described for each of 32 species. gravity is based on volume when green and weight Because color is an important identifying char- when ovendry. acteristic of many woods, special attention has been For information on botanical differences among paid to describing the natural color of a freshly cut species, such as the shape of leaves, patterns of surface of the wood. bark, and form of fruit, the reader is referred to Descriptions of species are accompanied by full- Trees, the 1949 Yearbook of the U. S. Department color illustrations showing grain pattern and other of Agriculture.

1 HARDWOODS (Broad-Leaved Species)

American beech (Fagus grandifolia)

Range.—The natural range of beech in the yields a short-fibered pulp that can be mixed with United States extends from Maine to northern longer fibered pulps to obtain paper of satisfactory Florida and westward from the Atlantic coast strength. into Wisconsin, Missouri, and Texas. It usually Uses.—American beech is used for lumber, grows in mixture with other species, although distilled products, veneer, railroad ties, pulpwood, pure stands of considerable extent occur in the cooperage, and fuel. The lumber is used largely Blue Ridge Mountains, especially in North in the manufacture of boxes, crates, baskets, Carolina. furniture, handles, flooring, woodenware, general Properties.— One of the heavy woods, American millwork, and novelties. Beech is especially beech has an average weight of 45 pounds a cubic suitable for food containers, since it does not foot and, with a specific gravity of 0.56, is classi- impart taste or odor. fied as hard. It is rated high in strength and Description.— Heartwood is white with a red- shock resistance and is readily bent when steamed. dish tinge to reddish brown. Pores are not visi- Beech is subject to very large shrinkage and ble but wood rays can be seen on all surfaces. requires considerable care during seasoning if On the end grain, the rays appear to be irregularly checks, warp, and discoloration are to be avoided. spaced, while on quartersawed surfaces they ap- Heartwood ranks low in resistance to decay. pear to be of different heights along the grain. The wood wears well and stays smooth when On the plainsawed surfaces, the rays also appear to subjected to friction, even under water. Although be of different height, but they look much nar- ranking high in nail-withdrawal resistance? it rower in this view. Beech is readily distinguish- has a tendency to split when nails are driven able from other native species by its weight, con- into it. When pulped by the soda process, beech spicuous rays, and tiny pores. (Illustration, p. 11.)

American sycamore (Platanus occidentalis)

Range.—American sycamore grows in scattered interlocking grain ranks high in its ability to with- groups or singly from southern Maine westward stand splitting. Sycamore wood does not impart to Nebraska and southward to eastern Texas and taste, odor, or stain to substances that come in northern Florida. It grows best on flatlands where contact with it. there is a good supply of ground water and along Uses.-The principal uses of American syca- the edges of streams. lakes. and swamps. At least more are for lumber, veneer, railroad ties, cooper- half of the stand of American sycamore is in the age, fence posts, and fuel. The lumber goes largely central and southern portions of its range in into furniture and boxes. Considerable sycamore Alabama, Arkansas, Indiana, Kentucky, Louisiana, veneer is used for fruit and vegetable baskets and Mississippi, Missouri, and Tennessee. berry boxes. Although generally used for the Properties.— In weight, American sycamore is cheaper grades of furniture, sycamore is used in ranked as a moderately heavy wood, averaging one form or another in practically all grades. Other 34 pounds a cubic foot. A moderately hard wood, products made from the lumber include flooring, with a specific gravity of 0.46, it has a close texture scientific instruments, handles, and butchers’ and an interlocking grain. It is moderately strong, blocks. moderately stiff, and has moderately good shock Description.— Heartwood is reddish brown or resistance. flesh brown in color. Pores are very small and not Sycamore has large shrinkage while drying, is visible to the unaided eye. Rays are visible on all inclined to warp, and is somewhat difficult to season. Also, it is not durable when exposed to surfaces. They appear uniformly spaced on the conditions favorable to decay. The wood turns end grain and of uniform height on quartersawed well on a lathe and keeps its shape well when bent surfaces. Plainsawed surfaces show rays that to form after steaming. It is only intermediate in appear more numerous and more closely spaced nail-withdrawal resistance but because of its than in beech. (Illustration, p. 11.)

2 Rock elm (Ulmus thomasii)

Range.—Rock elm grows from New Hampshire Uses.—Elm lumber is used principally for to Nebraska and as far south as Tennessee. containers and furniture. In some cases, the Much of the commercially important rock elm is different species of elm are employed indiscrim- located in Wisconsin and Michigan and more inately, but when hardness or shock resistance is than 80 percent of rock elm lumber and veneer required to a high degree, rock elm is preferred. comes from these 2 States. Rock elm veneer is used in considerable quantities Properties.— Rock elm is a heavy wood, averag- in manufacturing various types of containers, ing 44 pounds a cubic foot. The wood is clas- especially fruit and vegetable boxes and baskets. sified as hard, with a specific gravity of 0.57. It Large quantities of rock elm also go into is stronger, harder, and stiffer than any of the crating for heavy articles, such as furniture, glass, other commercial elms. With the exception of and porcelain. The strength and toughness of hickory and dogwood, rock elm has higher shock this wood make it very serviceable for certain resistance than any other American hardwood. types of containers that must stand rough usage, Although rock elm undergoes large shrinkage such as market baskets and bushel baskets for when drying, it tends to shrink somewhat less home use. Considerable quantities are used in than the other commercial elms. As with all the the manufacture of furniture, especially the bent parts of chairs. elms, care must be taken to prevent warp during Description.— Heartwood is brown to dark seasoning. Rock elm is somewhat difficult to brown, sometimes with shades of red. Summer- work with hand or machine tools, and the heart- wood pores are arranged in concentric wavy lines wood has low to moderate resistance to decay. that appear lighter than the background wood. However, all the commercial elms have excellent The springwood pores in rock elm are visible bending qualities. only upon magnification. (Illustration, p. 12.)

American elm (Ulmus americana)

Range.—American elm grows throughout the Uses.—American elm lumber is used principally eastern United States except in the Appalachian in the manufacture of containers, furniture, and highlands and southern Florida. About three- dairy and poultry supplies. Because of its excel- fourths of the stand of sawtimber size is located in lent bending properties, the wood has been much the Lake States and the Mississippi Delta region. used for barrels and kegs. Considerable quan- Wisconsin, Michigan, Louisiana, Arkansas, Ohio, tities of veneer go into the manufacture of fruit and Indiana have large volumes of elm. and vegetable boxes and baskets. American elm Properties.— American elm is moderately heavy, also is used a great deal for crating heavy articles, averaging 35 pounds a cubic foot, and moderately such as furniture, glass, and porcelain products. hard, with a specific gravity of 0.46. It rates as It is used in sizable quantities in the furniture moderately weak, but is moderately stiff and has industry, particularly for the bent parts of chairs. good shock resistance. Description.— Heartwood is brown to dark The wood of American elm has large shrinkage brown, sometimes containing shades of red. and care must be taken to prevent warping as it Although the summerwood pores are not visible seasons. Like all of the commercial elms, it has as individuals, they are arranged in concentric Its heartwood has excellent bending qualities. wavy lines within the boundaries of the growth low to moderate resistance to decay. The wood is slightly below average in woodworking proper- rings. The wavy lines appear lighter than the ties, but is among the top woods in ease of gluing. background wood. American elm shows a spring- In nail-withdrawal resistance, it has an inter- wood pore zone with a single row of large and mediate rank. easily visible pores. (Illustration, p. 12.)

3 Black walnut (Juglans nigra)

Range.—Black walnut grows naturally over a Uses.—The outstanding use of black walnut is large area extending from Vermont westward to for furniture. Large amounts are also used for Nebraska and southward to southern Georgia and gunstocks and interior finish, while smaller quan- southern Texas. The area of greatest commercial tities go into railroad tics, fence posts, and fuel- production is limited to the central part of this wood. In the furniture industry, it is used either as solid wood cut from lumber or as veneer and natural range. plywood. It also is extremely popular for interior Properties.—Black walnut is classified as a finish wherever striking effects are desired. The heavy wood, averaging 38 pounds a cubic foot. wood of black walnut is particularly suitable for The wood is hard, with a specific gravity of 0.51, gunstocks because of its ability to stay in shape is strong and stiff, and has good shock resistance. after seasoning, its fine machining properties, and Even under conditions favorable to decay, black its uniformity of texture. walnut heartwood is one of our most durable Description.— Heartwood is chocolate brown woods. It can be satisfactorily kiln-dried or air- and occasionally has darker, sometimes purplish, dried, and holds its shape well after seasoning. streaks. Unless bleached or otherwise modified, black walnut is not easily confused with any other Black walnut works easily with handtools and has native species. Pores are barely visible on the end excellent machining properties. The wood finishes grain but are quite easily seen as darker streaks beautifully with a handsome grain pattern. It or grooves on longitudinal surfaces. Arrangement takes and holds paints and stains exceptionally of pores is similar to that in the hickories and well, can be readily polished, and can be satis- persimmon, but the pores are smaller in size. factorily glued. (Illustration, p. 13.)

Black cherry (Prunus serotina)

Range.—Black cherry’s natural growth range is into lumber for various products. Much goes into throughout Maine westward to eastern North furniture and considerable amounts are used for Dakota and southward to central areas of Florida backing blocks on which electrotype plates, used and Texas. It also occurs in the mountain ranges in printing, are mounted. Other uses include of western Texas. The largest supplies of black burial caskets, woodenware and novelties, patterns cherry are believed to be located in the Appalach- and flasks for metalworking, plumbers’ woodwork, ian Mountains in New York, Pennsylvania, and and finish in buildings and railway coaches. West Virginia. Description.— Black cherry, which is not easily Properties.—Black cherry is a moderately confused with other native species because of its heavy wood with an average weight of 35 pounds distinctive color, has light to dark reddish brown a cubic foot. The wood is also moderately hard, heartwood. Although individual pores are not with a specific gravity of 0.47. Stiff and strong, visible to the naked eye, their pattern is some- it ranks high in resistance to shock. times distinctive. On end-grain surfaces, the Although it has moderately large shrinkage, pores may appear to form lines that parallel the black cherry stays in place well after seasoning growth rings, while on plainsawed surfaces, they and is comparatively free from checking and may follow the outline of the growth-ring boundary. The wood rays of cherry are barely visible on warping. It has moderate resistance to decay. end-grain surfaces and tend to produce a distinc- The wood is difficult to work with handtools but tive flake pattern on true quartersawed surfaces. ranks high in bending strength. It can be glued They are higher along the grain than those of satisfactorily with moderate care. walnut and hence show more prominently on Uses.—Nearly all the black cherry cut is sawed quartersawed surfaces. (Illustration, p. 13.)

4 Hickory (Carya)

Species names.—True hickories: shagbark hick- Hickory has very large shrinkage and must ory (Carya ovata), shellbark hickory (C. laciniosa), be carefully dried to avoid checking, warping, pignut hickory (C. glabra), and mockernut hickory and other seasoning defects. It has low decay (C. tomentosa). resistance but can be glued satisfactorily. Range.—The true hickories grow throughout Uses.—Nearly 80 percent of the true hickory most of the eastern United States except in used in the manufacture of wood products goes northern New England, the northern portions of into tool handles, for which its hardness, tough- Michigan and Wisconsm, and southern Florida. ness, stiffness, and strength make it especially suit- Close to 40 percent of the total stand of true able. Other uses include agricultural imple- hickory is located in the lower Mississippi Valley ments, athletic goods, and lawn furniture. region. Description.— Heartwood is brown to reddish Properties.— The wood of the true hickories is brown. Pores are visibly, but the zone of large very heavy, averaging from 42 to 52 pounds per pores is not sharply outlined as in oak and ash. cubic foot, and very hard, with a specific gravity Pores grade in size from one side of the annual ranging from 0.56 to 0.66. It also is very strong ring to the other. Wood rays are very small and as a post or beam, very stiff, and exceedingly high seen without magnification only on quartersawed in shock resistance. Some woods are stronger surfaces. Tyloses frequently plug the pores, than hickory and others are harder, but the com- making their outlines indistinct. Under mag- bination of strength, toughness, hardness, and nification, the end grain shows numerous white stiffness possessed by hickory has not been found lines paralleling the growth ring. (Illustration, to the same degree in any other commercial wood. p. 14.)

White ash (Fraxinus americana)

Range.—White ash grows throughout the entire and shovels. The wood is used too in the manu- eastern half of the United States except along the facture of furniture, where it is especially valuable Atlantic Coastal Plain, the gulf coast, and Florida. for the bent parts of chairs. Its good bending It is cut commercially everywhere except in the qualities also make it useful for cooperage. White extreme outer limits of this range and the lower ash is used almost exclusively for many types of Mississippi Valley. sports and athletic equipment, such as long oars Properties.— White ash is a heavy wood with and baseball bats. an average weight of 42 pounds a cubic foot. Description.—Heartwood is brown to dark Ranked as a hard wood, it has a specific gravity brown, sometimes with a reddish tint. As in of 0.55. It also is classified as strong and stiff, black ash, the zone of large pores is visible and and has good shock resistance. usually sharply defined. The white dots or lines The wood of white ash is noted for its excellent that indicate summerwood pores are usually bending qualities. In ease of working, tendency more prominent in white than in black ash. to split, and ability to hold nails and screws, it The small wood rays are generally visible only has moderately high rank. White ash lumber on quartersawed surfaces. can be rapidly and satisfactorily kiln-dried, and White ash is sometimes confused with hickory, it holds its shape well even under the action of but the two species are readily distinguishable. water. The wood remains smooth under con- The zone of large pores is more distinctive in tinual rubbing but is low in decay resistance. ash than in hickory. Also, the summerwood Uses.—The use of white ash that dwarfs all zone in ash shows white dots or lines that are others is its utilization for handles. It is the visible to the unaided eye, but in hickory these standard wood for D-handles for shovels and dots or lines are visible only upon magnification. spades and for long handles for forks, hoes, rakes, (Illustration, p. 14.)

5 Quaking aspen (Populus tremuloides)

Range.—Quaking aspen grows throughout most smooth surface. Aspen glues easily with a variety of the northeastern and western United States. of glues and under a wide range of gluing condi- The eastern part of its range extends from Maine tions. In painting properties, it ranks with the southward to Tennessee and westward to the best of the hardwoods. Dakotas. It is also found throughout the western Uses.—Aspen is used principally for lumber, United States except in the extreme Southwest. paper pulp, excelsior, and matches. The largest Commercial stands of aspen are located principally present-day use of the lumber is for boxes and in the Lake States and the Northeast, with smaller crates. It is probably most heavily used for pulp- amounts in the central Rocky Mountain region. wood, chiefly in the manufacture of book and Properties.— One of the lightweight hardwoods, magazine paper and corrugating and insulating quaking aspen averages 26 pounds a cubic foot. boards. Aspen has long been one of the preferred The wood is classified as soft, with a specific grav- woods for the manufacture of high-grade excelsior. ity of 0.35, and is weak, limber! and moderately Description.—Heartwood is white to very light low in shock resistance. brown, with occasional brown streaks associated Although aspen has moderately large shrinkage, with defects. Pores are very small and generally it can be seasoned satisfactorily by air-drying or not visible to the unaided eye. Growth rings are kiln-drying. In fact, few of the hardwoods shrink usually faint. Wood rays are small, uniform in as little as aspen. The wood ranks low in decay height along the grain, and visible only on quarter- resistance. It also is low in nail-withdrawal resist- sawed surfaces. Aspen is similar to cottonwood, ance, but has little tendency to split under the but cottonwood tends to have barely visible pores. action of nails or screws. It is worked easily with The growth rings in aspen are generally narrower hand or power tools and is fairly easy to finish to a than those in cottonwood. (Illustration, p. 15.)

American basswood (Tilia americana)

Range.—Basswood grows throughout the east- Uses.—Most of the basswood cut in this country ern half of the United States from Maine westward is first made into lumber for a variety of items. to North Dakota and southward to Florida and The largest amounts are used for crates and boxes. eastern Texas. More than half of the total stand The manufacture of sash, doors, and general mill- is located in the Lake States, and another quarter work also accounts for much of the basswood is in the east central part of the range. lumber produced each year. In addition consider- Properties.— Basswood is a lightweight hard- able lumber and veneer is used in the furniture wood with an average weight of 26 pounds a cubic industry, especially as core material overlaid with foot. The wood is weak, moderately stiff, and low high-grade furniture veneers, such as walnut and in resistance to shock. Its specific gravity of 0.32 mahogany. classes it as soft. Description.— Heartwood is creamy white to Although it has large shrinkage, basswood is creamy brown or sometimes reddish. Pores are fairly easy to air-dry or kiln-dry and stays in place very small, as in aspen, and growth rings on plain- well after seasoning. It has low nail-withdrawal sawed surfaces are generally faint. Wood rays are broader and higher than in aspen, and the two resistance, but. well resists splitting while being species can be readily distinguished by comparing nailed. In decay resistance, it is low. The wood their quartersawed faces. While the rays of aspen is easy to work with tools, takes and holds paint are low and uniform in height, some of those in well, and is easily-glued. When pulped by the soda basswood are distinctly higher than others and process, basswood yields a soft, short-fibered, easily frequently darker than the background wood. bleached pulp. (Illustration, p. 15.)

6 Sweetgum (Liquidambar styraciflua)

Range.—Sweetgum grows from southwestern Sweetgum ranks above average in turning, Connecticut westward almost to Kansas and boring, and steam-bending properties but some- southward to eastern Texas and central Florida. what below average in the other machining prop- The commercial range in the United States is erties. Its heartwood can be finished in a wide confined largely to the moist lands of the lower variety of color effects and the sapwood can be Ohio and Mississippi Basins and to the lowlands readily stained if a darker color is desired. of the southeastern coast. Uses.-The principal uses of sweetgum are for Properties.— Sweetgum is a moderately heavy lumber, veneer, plywood, and slack cooperage. wood with an average weight of 36 pounds per The lumber goes principally into boxes and crates, cubic foot. The wood is hard, with a specific furniture, interior trim, and millwork. Veneer is gravity of 0.46, moderately strong when used as used mainly for boxes, crates, baskets, furniture, a beam or post, moderately stiff, and has moder- and interior woodwork. Some sweetgum is used ately high shock resistance. for crossties and fuel, and comparatively small Sweetgum has very large shrinkage in drying, amounts go into fencing, excelsior, and pulpwood. and the sapwood and heartwood require different Description.—Heartwood is reddish brown and drying processes. The heartwood has low to occasionally variegated with streaks of darker moderate decay resistance. In nail-holding ability color. Pores are so small that they are not and in ability to resist splitting by nails and screws, visible except upon magnification. Growth rings sweetgum is rated intermediate. The heartwood are usually indistinct or inconspicuous. Rays requires special treatment before gluing can be are visible on quartersawed faces. (Illustration, done with best results. p. 16.)

Black tupelo (Nyssa sylvatica)

Range.-Black tupelo grows in all States east wood generally requires special treatment before of the Mississippi River and as far west as central gluing to obtain the best results and it ranks below Texas in the southern part of its range. In the the average of 25 southern hardwoods in machin- northern and eastern parts of its range, it grows ing properties. In nail-withdrawal resistance and under a wide variety of conditions ranging from resistance to splitting under the action of nails, swamps to dry mountainsides, but in the South black tupelo has an intermediate rank. It can be readily pulped by the chemical and semichemical it is largely confined to well-drained locations. processes. The largest commercial cuts of black tupelo Uses.—Black tupelo is used mainly for lumber, lumber are made in the Southeastern States. veneer, and paper pulp, and to some extent for Properties.— A moderately heavy wood, black railway ties and cooperage. The lumber goes tupelo has an average weight of 35 pounds a cubic largely into shipping containers and furniture. foot. It is rated as hard, with a specific gravity Black tupelo has been used for many years in the of 0.46, and the heartwood is low to moderate in manufacture of book and similar grades of paper. resistance to decay. The wood is moderately weak Description.—Heartwood is pale to moderately when used as a beam or post, moderately limber, dark brownish gray or dirty gray. Pores are very small, as in sweetgum. Growth rings are generally and moderately high in ability to resist shock. inconspicuous to moderately distinct. Rays are Black tupelo has large shrinkage and a tendency visible on quartersawed surfaces, but show up less to warp while seasoning because of its interlocking prominently against the background color of the grain. Considerable care is required in the drying wood than the rays in sweetgum. (Illustration, process to produce straight, flat lumber. The p. 16.)

7 White oak (Quercus)

Species names.—The white oak group includes liquids. The heartwood itself is comparatively white oak (Quercus alba), chestnut oak (Q. prinus), decay resistant, generally more so than that of post oak (Q. stellata), overcup oak (Q. lyrata), the red oaks. White oaks are above average in swamp chestnut oak (Q. michauxii), bur oak all machining operations except shaping. (Q. macrocarpa), chinkapin oak (Q. muehlenbergii), Uses.—Most white oak is made into lumber swamp white oak (Q. bicolor), and live oak for flooring, furniture, general millwork, and boxes (Q. virginiana). and crates. Large amounts are used for flooring Range.—White oaks grow mainly in the and furniture and it is the outstanding wood for eastern half of the United States, although some tight barrels, kegs, and casks because of the species are found as far west as eastern Oregon, nonporous heartwood. It has long been the Washington, and California. Commercial white leading wood for the construction of ships and oaks grow east of a line from western Minnesota boats. to western Texas. Description.— Heartwood is grayish brown. Properties.—The white oaks are heavy woods, The outlines of the larger pores are indistinct averaging 47 pounds a cubic foot, and are very except in chestnut oak, which has open pores hard, with a specific gravity ranging from 0.57 in with distinct outlines. On smooth-cut, end-grain chestnut oak to 0.81 in live oak. Led by live surfaces, the summerwood pores are not distinct oak, they rank high in strength properties. as individuals. Wood rays are generally higher The wood of the white oaks is subject to large than in red oak, the larger ones ranging from ½ to shrinkage and seasoning must be done carefully 5 inches in height along the grain. As in red to avoid checking and warping. Pores of the oak, rays appear lighter in color than the back- heartwood, with the exception of chestnut oak, ground wood on end-grain surfaces and darker are usually plugged with tyloses, a frothlike than the background wood on side-grain surfaces. growth that makes the wood impervious to (Illustration, p. 17.)

Red oak (Quercus)

Species names.—The red oak group includes average in all machining operations except shap- northern red oak (Quercus rubra), black oak (Q. ing, and the heartwood ranks low to moderate in velutina), scarlet oak (Q. coccinea), shumard oak decay resistance. (Q. shumardii), pin oak (Q. palustris), Nuttall oak Uses.—Most of the red oak cut in this country (Q. nuttallii), southern red oak (Q. falcata), water is converted into flooring, furniture, millwork, oak (Q. nigra), laurel oak (Q. laurifolia), and boxes and crates, caskets and coffins, agricultural willow oak (Q. phellos). implements, boats, and woodenware. Consider- Range.—Red oaks grow quite generally east of able lumber is also used in building construction, the Great Plains except for a narrow coastal strip and some is exported. The hardness and wearing along the Gulf of Mexico and in Florida. The qualities of red oak have made it an important largest amounts of commercial timber are cut in flooring wood for residences. Preservative-treated Tennessee, Arkansas, Kentucky, and Missouri. red oak is used extensively for crossties, mine Properties.—The red oaks are similar in many timbers, and fence posts. properties to the white oaks. A major difference Description.—Heartwood is grayish brown with is that red oak, because it lacks tyloses in its a more or less distinctive reddish tint. Pores are pores, is extremely porous. A heavy wood, it commonly open, and the outlines of the larger averages 44 pounds a cubic foot and the average pores are distinct. On smoothly cut end-grain specific gravity of the more important species surfaces, the summerwood pores can be seen as ranges from 0.52 to 0.60. The wood is hard, stiff, individuals and readily counted when examined and has high shock resistance. with a hand lens. Wood rays are commonly Red oak undergoes large shrinkage while drying, ¼ to 1 inch high along the gram. On end-grain and seasoning must be done carefully to avoid surfaces, rays appear as lines crossing the growth checking and warping. It is considerably above rings. (Illustration, p. 17.)

8 Yellow birch (Betula alleghaniensis)

Range.—Yellow birch grows in the Lake States, The lumber and veneer go mostly into furniture, New England, New York, New Jersey, Pennsyl- boxes, baskets, crates, woodenware, interior finish, vania, and along, the Appalachian Mountains into and general millwork. It is because of its pleasing southern Georgia. It reaches its best development grain pattern and ability to take a high polish, that near the Canadian border, and more than half of yellow birch is widely used in the furniture in- the stand is located in Michigan. The largest dustry. Spools, bobbins, and other turned articles amounts of lumber are produced in Michigan and are also important products. Wisconsin. Yellow birch is one of the principal woods used Properties.— Yellow birch is heavy, averaging for hardwood distillation to produce wood alcohol, 43 pounds a cubic foot, and hard, with specific acetate of lime, charcoal, tar, and oils. It is used gravity averaging 0.55. The wood is strong, stiff, in smaller quantities for pulpwood and cooperage. and has very high shock resistance. Description.— Yellow birch heartwood is light reddish brown. Pores are very small, sometimes Yellow birch has very large shrinkage and must be seasoned carefully to prevent checking and just barely visible on smoothly cut end-grain warping. Like all commercial birches, it is low in surfaces, and are uniformly distributed through decay resistance. Although the wood is difficult the annual ring cross section. Pore lines are visible on longitudinal surfaces as very fine grooves that to work with handtools, it can be readily shaped by may even be seen through natural finishes. Wood machine and ranks high in nail-withdrawal re- rays may be seen only on quartersawed surfaces, sistance. where they appear to be of one size and of uniform Uses.—Yellow birch is used principally for height along the grain. Growth rings are moder- lumber, veneer, distilled products, and crossties. ately distinct on plainsawed surfaces. (Illustration, p. 18.)

Sugar maple (Acer saccharum)

Range.-Sugar maple grows from Maine to Uses.—Sugar maple is used principally for Minnesota and southward to eastern Texas and lumber, distilled products, veneer, crossties, and northern Mississippi, Alabama, and Georgia. paper pulp. Probably 90 percent of the lumber The largest stands are in the Lake States and the is manufactured into such products as flooring, Northeast. The tree grows singly or in groups furniture, boxes and crates, handles, woodenware, in mixed stands of hardwoods. and novelties. It is especially suitable for bowling Properties.— Sugar maple is heavy, averaging alleys, dance floors, and other flooring that is 44 pounds a cubic foot, and hard, with a specific subjected to hard use. Sugar maple is one of the gravity of 0.56. Strong and stiff, it has high principal woods used in the hardwood distillation resistance to shock. Although it has large shrink- industry for the production of charcoal, acetic age and presents some difficulties in drying, the acid, and wood alcohol. wood can be satisfactorily seasoned. Its resist- Description.—Heartwood is light reddish brown ance to decay is low to moderate. and sometimes shows greenish-black streaks near Sugar maple ranks high in nail-withdrawal injuries. Pores are extremely small and not visi- resistance and intermediate in ease of gluing. ble on any surface. Wood rays may be seen on the end grain and especially on quartersawed The wood takes stain satisfactorily and is capable faces, where the higher rays are distinctive of a high polish. Although generally straight- because of their color and size and smaller rays grained, sugar maple occasionally occurs with appear as fine lines between them. The wood curly, wavy, or bird’s-eye grain. The wood turns rays may also be seen on plainsawed surfaces as well on a lathe, is markedly resistant to abrasive very small darker colored flecks that are parallel wear, and is without characteristic taste or odor. to the grain of the wood. (Illustration, p. 18.)

9 Yellow-poplar (Liriodendron tulipifera)

Range.-Yellow-poplar grows in all the States for taking and holding paint, enamel, and stain east of the Mississippi River except Maine, New and can be glued satisfactorily. Yellow-poplar Hampshire, Vermont, and Wisconsin, and in parts containers do not impart taste or odor to food- of Oklahoma and Missouri. Virginia, North stuffs, and the wood can be easily pulped by the Carolina, South Carolina, Georgia, and Alabama chemical and semichemical processes. contain more than half of the yellow-poplar saw- Uses.—The principal uses of yellow-poplar are timber in the United States. for lumber, veneer, and pulpwood. The lumber Properties.— Moderately light in weight, yel- goes mostly into furniture, boxes and crates, low-poplar averages 30 pounds a cubic foot. The interior finish, siding, fixtures, and musical instru- wood is classed as moderately soft, with a specific ments. The veneer is used extensively for finish, gravity of 0.40, and is moderately low in bending furniture, and various forms of cabinetwork. and compressive strength, moderately stiff, and Description.—Heartwood is brownish yellow, moderately low in shock resistance. Although it usually with a definite greenish tinge. The wood undergoes moderately large shrinkage when dried rays, as seen on a smoothly cut end-grain surface, from a green condition, it is not difficult to season are somewhat more prominent than in cucumber- and stays in place well when seasoned. The heart- wood is low to moderate in resistance to decay. tree. Positive identification of yellow-poplar and Yellow-poplar ranks intermediate in machining cucumbertree is best accomplished microscopically, properties. Although low in nail-withdrawal but it is possible to separate them on the basis of resistance, it has little tendency to split when gross features when both woods are at hand. nailed. Also, the wood has an excellent reputation (Illustration, p. 19.)

Cottonwood (Populus)

Species names.—Eastern cottonwood (Populus warp is to be avoided. The heartwood has low deltoides ), swamp cottonwood (P. heterophylla), decay resistance and the wood is rather difficult and black cottonwood (P. trichocarpa). to work with tools without producing chipped or Range.—Eastern and swamp cottonwood grow fuzzy grain. Cottonwood is low in nail-with- in small scattered stands or in mixture with other drawal resistance but does not, split easily when species. They range from southern New England nailed. The wood is classed among those that westward to the southern part of the Lake States glue satisfactorily with moderate care. It has a and southward to northern Florida and eastern good reputation for holding paint. Texas, except in the Appalachian highlands from Uses.—A large proportion of the annual output New York to Georgia and in the Ozark Mountains of cottonwood is cut into lumber and veneer and of Arkansas and Missouri. Black cottonwood then remanufactured into containers and furniture. grows in the Pacific Coast States and in western Both lumber and veneer are used in the furniture Montana, northern Idaho, and western Nevada. industry for core material, which is overlaid with Properties.—The cottonwoods are moderately high-grade furniture veneers. light in weight, ranging from 24 to 28 pounds a Description.— Heartwood of all three cotton- cubic foot. With a specific gravity of 0.37, wood species is grayish white to light grayish eastern cottonwood is classified as moderately brown with occasional streaks of light brown. soft, while black cottonwood’s specific gravity of The annual rings are rather wide. Pores are 0.32 classifies it as soft. The cottonwoods are barely visible on smooth cut, end-grain surfaces. Aside from the color of the heartwood, cottonwood moderately weak in bending and compression, is extremely similar to black willow. Separation moderately limber, and moderately low in shock of the two species is based mainly on heartwood resistance. color, which is light brown or reddish brown in Moderately large shrinkage is a characteristic willow, or on microscopic examination if only of cottonwood and it requires careful seasoning if sapwood material is available. (Illustration, p. 19.)

10 American beech American sycamore

11 Rock elm American elm

12 Black walnut Black cherry

13 True hickory White ash

14 Quaking aspen Basswood

15 Sweetgum Black tupelo

16 White oak Red oak

17 Yellow birch Sugar maple

18 Yellow-poplar Eastern cottonwood

19 Baldcypress Redwood

20 Incense-cedar Western redcedar

21

Sitka spruce Engelmann spruce

23 Sugar pine Western white pine

24 Western larch Douglas-fir

25 Western hemlock White fir

26 SOFTWOODS (Cone-Bearing Species)

Baldcypress (Taxodium distichum)

Range.—Baldcypress grows along the Atlantic building construction, especially where decay Coastal Plain from Delaware to Florida and west- resistance is required. It is frequently used for ward along the gulf coast nearly to the Mexican posts, beams, and other members in warehouses, border in Texas and up the Mississippi Valley to docks, factories, and bridges. Because of its high southern Indiana. The heaviest stands occur in degree of resistance to decay, it is particularly the swamps of the lower Mississippi Valley and valuable for greenhouses, stadium seats, cooling Florida. towers, and roof planks of dye houses. Properties.— Baldcypress is moderately heavy, Cypress is also used extensively for caskets and with an average weight of 32 pounds a cubic foot, burial boxes and for sash, doors, blinds, interior and moderately hard, with a specific gravity of trim and paneling, and general millwork. Con- 0.42. The wood is also moderately strong and tainers, such as boxes, crates, vats, tanks, and moderately stiff. Its durability under conditions tubs, require considerable quantities. favorable to decay is outstanding. Description.—Heartwood varies in color from Since green baldcypress lumber contains con- pale brown to blackish brown and sometimes has siderable moisture, it requires more care and time a reddish tinge. The wood is without resin canals, to kiln-dry than many other softwoods. However, and transition from springwood to summerwood the wood has moderately small shrinkage and is abrupt, as in redwood. Heartwood of darker slow air-drying is successfully practiced. It does specimens generally has a more or less rancid odor not impart taste, odor, or color to food products. and longitudinal surfaces feel distinctly greasy Uses.—The principal use of baldcypress is in or waxy. (Illustration, p. 20.)

Redwood (Sequoia sempervirens)

Range.— Redwood grows along or near the coast seasoning. Redwood has only intermediate nail- of California in a narrow, irregular strip not more withdrawal resistance but takes and holds paint than 35 miles wide and about 500 miles long, ex- exceptionally well. Redwood, the cedars, and tending from 100 miles south of San Francisco to a baldcypress make up the group of woods with the little above the Oregon border. This massive tree highest resistance to termites. does not grow naturally outside this area, which is Uses.—Probably from one-half to two-thirds of characterized by frequent fogs and considerable the redwood lumber produced is used in the form soil moisture. Single acres of redwood have been of planks, dimension, boards, joists, and posts. A found that contained over 1 million board-feet of large part of this material goes into framing for lumber. houses and industrial buildings, and into bridges, Properties.— Typical virgin-growth redwood is trestles, and other heavy construction. Much of moderately light in weight, averaging 28 pounds a the remaining lumber is remanufactured into house cubic foot: The wood is moderately hard, with a siding, sash, blinds, doors, general millwork, out- specific gravity of 0.38, moderately strong, and door furniture, and tanks. Richly colored red- moderately stiff. Except for shock resistance, it wood paneling provides pleasing interior effects. has somewhat higher strength properties for its Description.— Heartwood is usually a uniform weight than would be expected. deep reddish brown. The wood is without resin Redwood is thought to owe its outstanding decay canals and has no distinctive odor, taste, or feel. resistance to the reddish extractive in the tree, Western redcedar may approach redwood in color, which colors the wood and accounts for its name. but the distinctive odor of western redcedar sepa- The wood has very small shrinkage, is compara- rates the two woods immediately. (Illustration, tively easy to season, and holds its shape well after p. 20.)

27 Incense-cedar (Libocedrus decurrens)

Range.—Incense-cedar grows from southwest- all the high-grade lumber is used in the manu- ern Oregon southward through California in to facture of pencils and venetian blinds. Since Mexico and Lower California, with some small most incense-cedar lumber is more or less pecky, stands in western Nevada. Most of the com- it is used locally for rough construction. The mercial cut is confined to the Sierra Nevada qualities of incense-cedar that adapt it particularly Mountains in California and the mountain regions to pencil manufacture are straightness of grain, of northern California and southern Oregon. softness, and ease of whittling. Its decay re- Properties.— A lightweight wood, incense-cedar sistance makes it well suited for fence posts and averages 26 pounds per cubic foot. The wood is crossties. moderately soft, with a specific gravity of 0.35, Description.—Heartwood is reddish brown to moderately weak, limber, and low in shock dull brown, with an occasional tinge of lavender. resistance. Heartwood has a characteristic cedarlike odor Incense-cedar has small shrinkage and is com- and acrid taste. Shavings placed on the tongue paratively easy to season with little checking for a few seconds give a slight burning sensation. or warping. It ranks among the most decay- Transition from springwood to summerwood is resistant woods, along with cypress, redwood, and more or less abrupt and makes the growth rings black locust. Also, the wood splits readily and prominent on flat-grained surfaces. It is easier evenly. and is easy to work with tools. Incense- to produce a smooth cut on the end grain of cedar is one of the woods that holds paint longest incense-cedar than on western redcedar. Al- and suffers least when protection against weather- though incense-cedar and western redcednr cannot ing becomes inadequate. always be separated with certainty on the basis Uses.—The principal uses of incense-cedar of gross features, they can be readily distinguished are for lumber, fence posts, and crossties. Nearly under the microscope. (Illustration, p. 21.)

Western redcedar (Thuja plicata)

Range.—Western redcedar grows in a belt along takes and holds paint very well and is exceptionally the western coast of North America from southern weather resistant. Alaska to northern California. From northern Uses.—The principal uses of western redcedar Washington the range extends as far inland as are for shingles, lumber, poles, posts, and piling. Montana and then spreads a limited distance The lumber goes largely into exterior siding for north and south on the western slopes of the houses, interior finish, greenhouse construction, Rocky Mountains. More than two-thirds of flumes, and structural timbers, with smaller the stand of sawtimber is located in the coast amounts being used in the manufacture of ships lowlands of Washington. and boats, caskets, boxes and crating, sash, doors, Properties.— Western redcedar is light in weight, and general millwork. Round western redcedar averaging 23 pounds a cubic foot. The wood is poles, most of which are treated with a preserva- moderately soft, with a specific gravity of 0.31, tive, are shipped to all parts of the United States weak as a beam or post, moderately limber, and for use as utility poles. low in ability to resist shock. In decay resistance, Description.—Heartwood is reddish or pinkish the heartwood ranks with the more durable woods. brown to dull brown. It has a characteristic The wood of western redcedar is not difficult cedarlike odor, but shavings placed on the tongue to kiIn-dry when proper methods are used, but do not give quite the sensation that incense-cedar requires more care in seasoning than other western shavings do. Transition from springwood to cedars. After it, has been properly dried, it stays summerwood is the same as in incense-cedar. in place well and has little tendency to warp. The wood is sometimes confused with redwood, but It is comparatively low in nail-withdrawal resist- the cedarlike odor of western redcedar separates ance but can be easily glued. Western redcedar the two species immediately. (Illustration, p. 21.)

28 Shortleaf pine (Pinus echinata)

Range.—Shortleaf pine, which has the widest Uses.—Shortleaf pine lumber is used prin- distribution of the southern pines, grows through- cipally for building material such as interior finish, out most of the southeastern United States. It is ceiling, frames, sash, sheathing, subflooring, and generally a tree of the uplands and foothills, but joists, and for boxes and crates, caskets, furniture, its range extends into the lower levels. Stands of woodenware, and novelties. Considerable use is shortleaf pine are concentrated in Arkansas, but also made of shortleaf pine for crossties, telephone Texas, Georgia, Alabama, and Mississippi also and telegraph poles, and mine timbers. In addi- contain large stands. Properties.— Shortleaf pine, a moderately heavy tion, the resin-rich heartwood is distilled to make wood but, ranking with the lightest of the im- wood turpentine, tar, and tar oils. Large amounts portant southern pines, has an average weight of of this southern pine are used for paper pulp. 36 pounds a cubic foot. Typically, the wood is Description.— Heartwood ranges from shades moderately hard, with a specific gravity of 0.46, of yellow and orange to reddish brown or light moderately strong, stiff, and moderately shock brown. Transition from springwood to summer- resistant. The heartwood is moderately decay wood is abrupt, with the annual rings prominent resistant. on all surfaces. Resin canals are large and abund- Like all southern pines, shortleaf has moderately ant and are easily found in all annual rings. large shrinkage but tends to stay in place well after seasoning. In nail-withdrawal resistance, it Summerwood bands are generally wider than ranks above hemlock, spruce, and Douglas-fir. those of ponderosa pine. In appearance, the wood And, like other southern pines, it produces a of shortleaf pine closely resembles that of long- resinous substance from which turpentine and leaf, loblolly, and slash, the other principal rosin can be made. southern pines. (Illustration, p. 22.)

Ponderosa pine (Pinus Ponderosa)

Range.-Ponderosa pine grows in every State Uses.—Ponderosa pine is used principally for west, of the Great Plains, with the largest stands lumber and, to a lesser extent, for piling, poles, and greatest commercial production in California, posts, mine timbers, veneer, and hewn ties. The Oregon, and Washington. The tree is found on a lumber has a variety of uses ranging from high- wide variety of soils, sites, and elevations and grade millwork to boxes and crates. For cabinets occurs both in pure stands and in mixture with and millwork, the clearer, softer material is used, other species. Because it can maintain itself on while the manufacture of boxes and crates con- dry sites, this tree is the principal species on areas sumes the lower grade lumber. Knotty ponderosa pine has come into wide use as paneling for interior of low rainfall. finish. Properties.— The wood of Ponderosa pine varies Description.—Heartwood is yellowish to light red- considerably in its properties. However, in the dish or orange brown. Transition from springwood outer portions of trees of sawtimber size, it gen- to summerwood is abrupt as in the southern pines, erally is moderately light in weight, averaging 28 but the summerwood bands are narrow. Growth pounds per cubic foot, and moderately soft, with rings are generally most prominent on the flat- a specific gravity of 0.38. This wood also ranks grained surfaces, which also frequently exhibit a as moderately weak, moderately limber, and mod- dimpled appearance. This appearance is common in erately low in shock resistance. It has moderately lodgepole pine too, but in lodgepole the dimples are smaller and more abundant. The resin canals of small shrinkage and little tendency to warp. ponderosa pine are abundant and easily found in Ponderosa pine compares favorably with woods all annual rings. They are larger than those in of similar density in nail-withdrawal resistance, is lodgepole pine, and the heartwood of lodgepole not easily split by nails, and glues easily. The pine is lighter colored than that of ponderosa. heartwood has low to moderate decay resistance. (Illustration, p. 22.)

29 Sitka spruce (Picea sitchensis)

Range.—Sitka spruce grows along the Pacific its long, strong fibers and the ease with which it coast from Alaska to northern California. It can be pulped by any of the pulping processes. is rarely found over 40 miles from the coast and Uses.—Sitka spruce is used principally for generally grows in mixture with Douglas-fir, lumber, cooperage, and paper pulp. Some of the grand fir, western hemlock, and western redcedar. lumber is used for construction just as it comes It occasionally forms pure stands. from the sawmill, but the greater part is remanu- Properties.— Sitka spruce is a moderately light- factured into various products. At least half of weight wood, averaging 28 pounds a cubic foot. the remanufactured lumber goes into boxes and The wood also is moderately soft, with a specific crates. The other major uses of the lumber are gravity of 0.37, moderately weak in bending and for furniture, planing-mill products, sash, doors, compressive strength, moderately stiff, and moder- blinds, and general millwork. Specialty uses in- ately low in resistance to shock. On the basis clude aircraft, ladder rails, and piano sounding of weight, however, it ranks high in strength boards. properties. Description.— Heartwood is light pinkish yellow Although the wood has moderately large to pale brown. Transition from springwood to shrinkage, it is not difficult to kiln-dry. It works summerwood is gradual, making the annual rings easily, holds fastenings well, and can be obtained appear rather inconspicuous on flat-grained sur- in clear, straight-grained pieces of large size and faces. Resin canals are usually more prominent than in the other spruces. On end-grain sur- uniform texture with hardly any hidden defects. faces, the canals appear as small dots or very Its decay resistance is low. Although planed short lines that run parallel to the growth ring. surfaces of Sitka spruce lumber may show a silky Flat-grained surfaces are lustrous and frequently sheen, the wood has a tendency to produce wooly exhibit dimpling. The pinkish color of the heart- or fuzzy grain under the action of planer knives. wood distinguishes this species from all other As a pulpwood, Sitka spruce ranks high because of spruces. (Illustration, p. 23.)

Engelmann spruce (Picea engelmannii)

Range.—In the United States, Engelmann Uses.—Engelmann spruce is used principally spruce grows along the upper slopes of the Cascade for lumber and to a lesser extent for mine timbers, Mountains in Washington, Oregon, and the ex- crossties, and poles. A large proportion of the treme northern part of California, and in the Rocky lumber goes into building construction and boxes. Mountains in northeastern Washington, north- Much of it is used for subflooring, sheathing, and eastern Oregon, Idaho, Montana, Wyoming, Colo- studding. Some Engelmann spruce is pulped for rado, Utah, Arizona, and New Mexico. The paper. largest producers of Engelmann spruce are Colo- Description.— Heartwood is not distinct from rado, Montana, and Idaho. sapwood and ranges from nearly white to pale Properties.— Engelmann spruce is rated as light yellowish brown. Transition from springwood to in weight, averaging 24 pounds a cubic foot. The summerwood is somewhat more abrupt than in the wood is soft, with a specific gravity of 0.32, and is other spruces. Resin canals are present, but are weak as a beam or post, moderately limber, and frequently difficult to find. They appear on very low in ability to resist shock. smoothly cut, end-grain sections as small white Engelmann spruce can be readily air-dried with dots and on longitudinal surfaces as short, light- little tendency to warp. It has moderately small shrinkage and stays in place well when properly brown streaks or very fine grooves. The wood of dried. The wood is low in decay resistance but all the spruces, with the exception of Sitka, is very glues easily under a wide range of gluing condi- similar in its gross and microscopic features and tions. Engelmann space has excellent pulping therefore almost impossible to tell apart. (Illus- and papermaking properties. tration, p. 23.)

30 Sugar pine (Pinus lambertiana)

Range.—Sugar pine grows from the Coast and Uses.—Sugar pine is used almost entirely for Cascade Mountain Ranges of southern Oregon, lumber in buildings, boxes and crates, sash, doors, along the Coast Range and the Sierra Nevada frames, general millwork, and foundry patterns. of California, through southern California in It is suitable for all phases of house construction, scattered stands, and into Mexico. The heaviest with the high-grade material going into interior stands and largest trees are found in California and exterior trim, siding, and paneling, while the from Tulare to Eldorado Counties, in cool, moist lower grade material is used for sheathing, sub- flooring, and roof boards. sites on the west slope of the Sierra Nevada at The wood also has proved very satisfactory for elevations of 4,000 to 7,000 feet. containers because of its light weight and color, Properties.— Sugar pine is lightweight, averag- nailing properties, and freedom from taste and ing 25 pounds a cubic foot. The wood is moder- odor. Sugar pine is widely used for foundry ately soft, with a specific gravity of 0.35, moder- patterns because it meets the exacting require- ately limber, moderately weak, and low in shock ments and is readily available in wide, thick resistance. pieces practically free from defects. Description.— Heartwood is light brown to pale In decay resistance, sugar pine heartwood is reddish brown. Resin canals are abundant and rated low to moderate. The wood has very small commonly stain the surface of the wood with shrinkage, seasons readily without checking or resin. Transition from springwood to summer- warping, and stays in place well. It is easy to wood is gradual; making the growth rings appear work with tools, does not split easily in nailing, less prominent on flat-grained surfaces. (Illustra- and has moderate nail-withdrawal resistance. tion, p. 24.)

Western white pine (Pinus monticola)

Range.—Western white pine grows from the split easily in nailing and occupies an intermediate Canadian border southward into western Montana position in nail-withdrawal resistance. and northern Idaho, and along the Cascade and Uses.-Practically all of the western white pine Sierra Nevada Mountains through Washington cut is sawed into lumber. About three-fourths of and Oregon to central California. The heaviest this lumber is used in building construction. The stands occur in northern Idaho and in adjacent lower grades are used for subflooring and wall and parts of Montana and Washington. The trees roof sheathing, while the high-grade material is usually grow in mixture with western hemlock, made into siding of various kinds, exterior and western redcedar, western larch, grand fir, and interior trim, partition, casing, base, and paneling. Douglas-fir, but occasionally occur in pure stands Other uses of western white pine include match on limited areas. planks, boxes, and millwork products. Properties.-Moderately light in weight, west- Description.—Heartwood is cream colored to ern white pine averages 27 pounds a cubic foot. light brown or reddish brown. Resin canals are The wood is moderately soft, with a specific abundant and transition from springwood to gravity of 0.36, weak, moderately stiff, and mod- summerwood is like that in sugar pine. Separation erately low in ability to resist shock. of western white pine and sugar pine is generally Although the wood has moderately large shrink- accomplished on the basis of the resin canals. age, it is easy to kiln-dry and stays in place well which are larger in sugar pine than in the other after seasoning. In decay resistance, it is ranked white pines. Microscopic characteristics, however, as low to moderate. Western white pine works offer a more reliable means of differentiation than easily with tools and glues readily. It does not gross features. (Illustration, p. 24.)

31 Western larch (Larix occidentalis)

Range.—Western larch grows in mountain high in nail-withdrawal resistance, small or blunt- valleys and on slopes at elevations of 2,000 to pointed nails are preferred to reduce splitting. 7,000 feet in Washington, Oregon, western Mon- Uses.—Western larch is used principally in tana, and northern Idaho. It reaches its best building construction as rough dimension, small development and greatest commercial importance timbers, planks, and boards. Considerable in northern Idaho and western Montana, where it amounts also are made into crossties and mine is generally associated with other species, although timbers. Probably three-fourths of the lumber sometimes forming pure forests of limited extent. produced is used for structural purposes as it Properties.— A heavy wood, western larch has comes from the sawmill. Some of the high-grade an average weight of 38 pounds per cubic foot. lumber is remanufactured into interior finish, Also, it is moderately hard, with a specific gravity flooring, sash, doors, blinds, and other products. of 0.51, stiff, strong, and moderately high in Description.—Heartwood is russet brown and shock resistance. the color is best seen in summerwood bands on Western larch and Douglas-fir are frequently flat-grained surfaces. Resin canals are present, but are very small and difficult to find unless the logged together and sold in mixture under the resin has stained the wood surfaces or the exuda- commercial name of “larch-fir.” Heartwood of tion actually appears as very small droplets. both species is moderately decay resistant. West- Transition from springwood to summerwood is ern larch has large shrinkage in drying and presents abrupt and there is little difference in color be- seasoning problems because of the slowness with tween the two zones. The heartwood lacks a which it gives up its moisture. Although it ranks distinctive odor. (Illustration, p. 25.)

Douglas-fir (Pseudotsuga menziesii)

Range.-In the United States, Douglas-fir soft pines, it holds fastenings well and can be glued grows in most forests from the Rocky Mountains satisfactorily. Dense heartwood has moderate to the Pacific coast and from the Mexican to decay resistance. Canadian borders. Botanically it is not a true Uses.—The principal uses of Douglas-fir are fir. It reaches its largest size and fastest rate of for lumber, timbers, piling, and plywood. Re- growth in Washington and Oregon, where large manufactured lumber. goes mostly into sash, doors, trees form very dense forests that sometimes general millwork, railroad car construction and yield as much as 100,000 board-feet of lumber repair, and boxes and crates. Plywood is now in per acre. wide use for sheathing, concrete forms, prefabrica- Properties.— Most old-growth Douglas-fir from ted house panels, millwork, ships and boats, and the Pacific coast and northern Rocky Mountain other structural forms. Chipped Douglas-fir saw- States is moderately heavy, very stiff, moderately mill residue has a considerable market at pulp mills. strong, and moderately shock resistant. It aver- Description.—Heartwood is orange red to red ages about 33 pounds a cubic foot. The wood is or sometimes yellowish. Resin canals, which are also moderately hard, with an average specific seen as brownish streaks in the summerwood, gravity ranging from 0.40 to 0.48. Wide-ringed appear to be more abundant and more readily second-growth Douglas-fir from the coastal States detectable than in western larch. Transition from and material grown in the southern Rocky Moun- springwood to summerwood is similar to that in tain States tends to be lighter in weight and to western larch. The heartwood of Douglas-fir may have lower strength properties. be confused with that of the southern yellow pines, The wood of Douglas-fir can be readily kiln- but resin canals are larger and much more abun- dried if proper methods are used. Although it is dant in southern pines. Most Douglas-fir has a more difficult to work with handtools than the distinctive odor. (Illustration, p. 25.)

32 Western hemlock (Tsuga heterophylla)

Range.—Western hemlock grows along the Pa- ping papers, and viscose and other cellulose deriva- cific coast from Alaska to San Francisco Bay, and tives. Although little western hemlock goes into as far inland as northern Idaho and northwestern heavy structural material, large quantities are Montana. The best stands are found in the humid used for sheathing, siding, subflooring, joists, stud- coastal regions of Oregon, Washington, and Alaska ding, planking, and rafters in light frame con- and on the lower slopes of the Cascade Mountains struction. in Washington and Oregon. Description.—Heartwood of western hemlock is Properties.— Western hemlock is moderately light reddish brown and frequently has a purplish light in weight, averaging 29 pounds a cubic foot, cast, especially in the summerwood bands. Tran- and moderately hard, with a specific gravity of sition from springwood to summerwood is gradual 0.38. It is also moderately weak and its shock re- and on end-grain surfaces there is little color con- sistance is fairly low. Although western hemlock trast between the two zones. The wood lacks has moderately large shrinkage, it is comparatively normal resin canals. easy to season. Heartwood is low in decay resist- Eastern hemlock heartwood is more roseate in ance but the wood is easy to work with tools and color than western hemlock and the transition from has satisfactory gluing properties. Excellent for springwood to summerwood is so abrupt that the papermaking, it yields a tough, strong, and easily two zones stand out distinctly. The coarser tex- bleached pulp. ture of eastern hemlock springwood tends to tear out in crosscut sawing and to produce a ribbed ap- Uses.—Western hemlock is used primarily for pearance on the end grain. A smooth cut is diffi- pulpwood and construction lumber and, to a cult to make on the end grain of eastern hemlock, limited extent, for containers, plywood core stock, even with a very sharp knife, while western hem- crossties, and mine timbers. The pulp is used for lock cuts very easily and produces smooth surfaces. newsprint and other printing paper, tissues, wrap- (Illustration, p. 26.)

White Fir (Abies)

Species names.—White fir (Abies concolor), Uses.-White fir is used principally for lumber grand fir (A. grandis), Pacific silver fir (A. ama- and pulpwood. The lumber goes largely into bilis), California red fir (A. magnifica), and noble building construction, planing-mill products, boxes fir (A. procera). and crates, sash, doors, frames, and general mill- Range.-Commercial white fir, which includes work. Probably 75 percent or more of all white all the above species, grows throughout the fir lumber is used for framing, subflooring, and Pacific Coast and Rocky Mountain States. The sheathing of houses. Pulpwood is used chiefly largest, stands of white fir (A. concolor) probably in the manufacture of various grades of printing occur in California, but other States contain paper and high-grade wrapping paper. larger stands of the other species. Description.— Heartwood is nearly white to Properties.— Commercial white fir is light in pale reddish brown and the wood lacks normal weight, the various species ranging from 26 to 28 resin canals. Transition from springwood, like pounds a cubic foot. It is moderately soft, with that in eastern hemlock, is more abrupt than an average specific gravity of 0.35, moderately in western hemlock. Also, color of springwood weak, moderately low in shock resistance, mod- and summerwood on end-grain surfaces is more contrasting than in western hemlock. The bal- erately stiff, and low in nail-withdrawal resistance. sam fir of the east is more uniformly white in It is difficult to season, a fact that retarded its use color, with less contrasting rings than the western until satisfactory seasoning methods were devel- firs. Wood rays of the western firs frequently oped. Also, its decay resistance is low, but gluing contain colored material that makes them stand properties are satisfactory. White fir produces out more on edge-grained surfaces than rays of strong, high-quality paper pulp. the eastern firs, which are generally colorless. (Illustration, p. 26.)

33 GLOSSARY

Annual growth ring.—The growth layer put on in a single Dry kiln.-(See Kiln.) growth year, including springwood and summerwood. Dry rot.-A term loosely applied to any dry, crumbly rot Bark.—Outer layer of a tree, comprising the inner bark, but especially to that which, when in an advanced or thin, inner living part (phloem) and the outer stage, permits the wood to be crushed easily to a dry bark, or corky layer, composed of dry, dead tissue. powder. The term is actually a misnomer, since all Beam.—A structural member supporting a load applied wood-rotting fungi require considerable moisture transversely to it. for growth. Bending, steam.—The process of forming curved wood Early wood.—(See Springwood.) members by steaming or boiling the wood and bending Edge-grained.—(See Grain.) it to a form. Extractives.— Substances in wood, not an integral part of Bird’s-eye.— Small localized areas in wood with the fibers the cellular structure, that can be removed by solution indented and otherwise contorted to form few to in hot or cold water, ether, benzene, or other solvents many small circular or elliptical figures remotely that do not react chemically with wood components. resembling birds’ eyes on the tangential surface. Fiber, wood.—A comparatively long (one twenty-fifth or Common in sugar maple and used for decorative less to one-third inch), narrow, tapering wood cell purposes: rare in other hardwood species. closed at both ends. Bow.-The distortion in a board that deviates from flat- Figure.— The pattern produced in a wood surface by annual ness lengthwise but not across its faces. growth rings, rays, knots, deviations from regular Broad-leaved trees.—(See Hardwoods.) grain such as interlocked and wavy grain, and irregular Cambium.—The one-cell-thick layer of tissue between the coloration. bark and wood that repeatedly subdivides to form Finish.—Wood products to be used in the joiner work, new wood and bark cells. such as doors and stairs, and other fine work required Cell.—A general term for the minute units of wood to complete a building, especially the interior. structure, including wood fibers, vessels members, Flakes.—(See Rays, wood.) and other elements of diverse structure and function. Flat-grained.—(See Grain.) Check.—A lengthwise separation of the wood, usually Framing.— Lumber used for the structural members of a extending across the rings of annual growth and building, such as studs and joists. commonly resulting from stresses set up in the wood Girder.— A large or principal beam used to support con- during seasoning. centrated loads at points along its length. Collapse.—The flattening of groups of cells in heartwood during the drying or pressure treatment of wood, Grade.-The designation of quality of a manufactured characterized by a caved-in or corrugated appearance. piece of wood or of logs. Crook.—The distortion in a board that deviates edgewise Grain.—The direction, size, arrangement, appearance, or from a straight line from end to end of the board. quality of the elements in wood or lumber. To have a Cup.—The distortion in a board that deviates flatwise specific meaning the term must be qualified. from a straight line across the width of the board. Close-grained wood.—Wood with narrow, inconspicuous Decay.— The decomposition of wood substance by fungi. annual rings. The term is sometimes used to desig- Advanced (or typical) decay.-The older stage of decay nate wood having small and closely spaced pores, but in which the destruction is readily recognized because in this sense the term “fine textured” is more often the wood has become punky, soft and spongy, stringy, used. ringshaked, pitted, or crumbly. Decided discolora- Coarse-grained wood.—Wood with wide conspicuous tion or bleaching of the rotted wood is often apparent. annual rings in which there is considerable difference Incipient decay.—The early stage of decay that has between springwood and summerwood. The term is not proceeded far enough to soften or otherwise sometimes used to designate wood with large pores, perceptibly impair the hardness of the wood. It is such as oak, ash, chestnut, and walnut, but in this usually accompanied by a slight discoloration or sense the term “coarse textured” is more often used. bleaching of the wood. Cross-grained wood.—Wood in which the fibers deviate Density.—The weight of a body per unit volume. When from a line parallel to the sides of the piece. Cross expressed in the c. g. s. (centimeter-gram-second) grain may be either diagonal or spiral grain, or a system, it is numerically equal to the specific gravity combination of the two. of the same substance. Curly-grained wood.—Wood in which the fibers are Diffuse-porous wood.—Certain hardwoods in which the distorted so that they have a curled appearance, as pores tend to be uniform in size and distribution in “bird’s-eye” wood. The areas showing curly grain throughout each annual ring or to decrease in size may vary up to several inches in diameter. slightly and gradually toward the outer border of the Diagonal-grained wood.—Wood in which the annual ring. rings are at an angle with the axis of a piece as a Dimension.—(See Lumber.) result of sawing at an angle with the bark of the tree Dimension stock.—A term largely superseded by the term or log. A form of cross grain. hardwood dimension lumber. It is hardwood stock Edge-grained lumber.—Lumber that has been sawed so processed to a point where the maximum waste is that the wide surfaces extend approximately at right left at a dimension mill, and the maximum utility is angles to the annual growth rings. Lumber is con- delivered to the user. It is stock of specified thickness, sidered edge grained when the rings form an angle of width, and length, in multiples thereof. According to 45° to 90° with the wide surface of the piece. specification, it may be solid or glued; rough or sur- Fine-grained wood.—(See Grain, close-grained wood.) faced; semifabricated or completely fabricated. Flat-grained lumber.—Lumber that has been sawed so Dimensional stabilization.—Reduction through special the wide surfaces extend approximately parallel to the treatment in swelling and shrinking of wood, caused annual growth rings. Lumber is considered flat by changes in its moisture content with changes in grained when the annual growth rings make an angle relative humidity. of less than 45° with the surface of the piece.

34 Grain—Continued Medullary rays.—(See Rays, wood.) Interlocked-arained wood.—Wood in which the fibers are Millwork.— Generally, all building materials made of inclined in one direction in a number of rings of annual finished wood and manufactured in millwork plants growth, then gradually reverse and are inclined in an and planing mills. Includes such items as inside opposite direction in succeeding growth rings, then and outside doors, window and door frames, blinds, reverse again. porch work, mantels, panel work, stairways, moldings, Open-grained wood.—Common classification by painters and interior trim. Does not include flooring, ceiling, for woods with large pores, such as oak, ash, chestnut, or siding. and walnut. Also known as “coarse textured.” Moisture content of wood.—The amount of water contained Plainsawed lumber.—Another term for flat-grained in the wood. Usually expressed as a percentage of lumber. the weight of the ovendry wood. Quartersawed lumber.—Another term for edge-grained Naval stores.—A term applied to the oils, resins, tars, and lumber. pitches derived from oleoresin contained in, exuded by, Spiral-grained wood.—Wood in which the fibers take a or extracted from trees chiefly of the pine species spiral course about the trunk of a tree instead of the (genus Pinus) or from the wood of such trees. normal vertical course. The spiral may extend in a Old growth.—Timber growing in or harvested from a right-handed or left-handed direction around the tree mature, naturally established forest. When the trees trunk. Spiral grain is a form of cross grain. have grown most or all of their individual lives in Straight-grained wood.—Wood in which the fibers run active competition with their companions for sun- parallel to the axis of a piece. light and moisture, this timber is usually straight Vertical-grained lumber.—Another term for edge-grained and relatively free of knots. lumber. Ovendry wood. Wood dried to constant weight in an Wavy-grained wood.—Wood in which the fibers collec- oven at temperatures above that of boiling water tively take the form of waves or undulations. (usually 101° to 105° C. or 214° to 221° F.). Green.—Freshly sawed lumber, or lumber that has received Peck.—Pockets or areas of disintegrated wood caused by no intentional drying; unseasoned. The term does advanced stages of localized decay in the living tree. not apply to lumber that may have become completely It is usually associated with cypress and incense- wet through waterlogging. cedar. There is no further development of peck Hardwoods.— Generally, the botanical group of trees that once the lumber is seasoned. have broad leaves, in contrast to the conifers or soft- Pitch pocket.—An opening that extends parallel to the woods. The term has no reference to the actual annual growth rings and that contains, or has con- hardness of the wood. tained, either solid or liquid pitch. Heartwood.— The wood extending from the pith to the Pitch streak.—A well-defined accumulation of pitch in a sapwood, the cells of which no longer participate in more or less regular streak in the wood of certain the life processes of the tree. Heartwood may be softwoods. infiltrated with gums, resins, and other materials that Pith.—The small, soft core occurring in the structural usually make it darker and more decay resistant than center of a tree trunk, branch, twig, or log. sapwood. Plainsawed.— (See Grain.) Honeycombing.—Checks, often not visible at the surface, Planing-mill products.—Products worked to pattern, such that occur in the interior of a piece of wood, usually as flooring, ceiling, and siding. along the wood rays. Plywood.— An assembly made of layers (plies) of veneer, or Joint.—The junction of two pieces of wood or veneer. of veneer in combination with a lumber core, joined Joist.—One of a series of parallel beams used to support with an adhesive. The grain of adjoining plies is floor and ceiling loads and supported in turn by larger usually laid at right angles, and almost always an odd beams, girders,-or bearing walls. number of plies are used to obtain balanced con- Kiln.—A heated chamber for drying lumber, veneer, and struction. other wood products. Pore.—(See Vessels.) Knot.—That portion of a branch or limb which has been Porous woods.—Another name for hardwoods, which fre- surrounded by subsequent growth of the wood of the quently have vessels or pores large enough to be seen trunk or other portion of the tree. As a knot appears readily without magnification. on the sawed surface, it is merely a section of the Preservative.—Any substance that is effective, for a reason- entire knot, its shape depending upon the direction able length of time, in preventing the development of the cut. and action of wood-rotting fungi, borers of various Longitudinal.— Generally, the direction along the length kinds, and harmful insects that deteriorate wood. of the grain of wood. Quartersawed.—(See Grain.) Lumber.—The product of the saw and planing mill, not Radial.—Coincident with a radius from the axis of the tree further manufactured than by sawing, resawing, pass- or log to the circumference. A radial section is a ing lengthwise through a standard planing machine, lengthwise section in a plane that extends from pith cross-cutting to length, and matching. to bark. Boards.— Yard lumber less than 2 inches thick and 1 Rate of growth.—The rate at which a tree has laid on wood. or more inches wide. measured radially in the trunk or in lumber cut from Dimension.—Lumber from 2 inches to, but not including the trunk. The unit of measure in use is number of 5 inches thick, and 2 or more inches wide. annual growth rings per inch. Dressed size.—The dimensions of lumber after shrinking Rays, wood—Strips of cells extending radially within a tree from the green dimensions and being surfaced with 3 and varying in height from a few cells in some species a planing machine to usually /8 or ½ inch less than to 4 or more inches in oak. The rays serve primarily the nominal or rough size. For example, a 2- by 5 5 to store food and transport it horizontally in the tree. 4-inch stud actually measures 1 /8 by 3 /8 inches under American lumber standards for softwood lumber. Resin passage (or duct) .—Intercellular passages that con- Nominal size.—As applied to timber or lumber, the tain and transmit resinous materials. On a cut sur- rough-sawed commercial size by which it is known face, they are usually inconspicuous. They may ex- and-sold in the market. tend vertically parallel to the axis of the tree or at Structural lumber.—Lumber that is 2 or more inches right angles to the axis and parallel to the rays. thick and 4 or more inches wide. intended for use Ring-porous woods.—A group of hardwoods in which the where working stresses are required. The grading of pores are comparatively large at the beginning of each structural lumber is based on the strength of the annual ring and decrease in size more or less abruptly piece and the use of the entire piece. toward the outer portion of the ring, thus forming a Timbers.—Lumber 5 or more inches in least dimension. distinct inner zone of pores, known as the springwood, Timbers may be classified as beams, stringers, posts, and an outer zone with smaller pores, known as the caps, sills, girders, purlins, etc. summerwood.

35 Sap.—All the fluids in a tree except special secretions and Texture.—A term often used interchangeably with grain. excretions, such as oleoresin. Sometimes used to combine the concepts of density Sapwood.— The living wood of pale color near the outside and degree of contrast between springwood and of the log. Under most conditions the sapwood is summerwood. In this publication, texture refers to more susceptible to decay than heartwood. the finer structure of the wood (see Grain) rather than Seasoning.— Removing moisture from green wood in order the annual rings. to improve its serviceability. Twist.—A distortion caused by the turning or winding Air-dried.— Dried by exposure to air, usually in a yard, of the edges of a board so that the four corners of without artificial heat. any face are no longer in the same plane. Kiln-dried.— Dried in a kiln with the use of artificial heat. Second growth.—Timber that has grown after removal by Tyloses.— Masses of cells appearing somewhat like froth cutting, fire, wind, or other agency, of all or a large in the pores of some hardwoods, notably white oak part of the previous stand. and black locust. In hardwoods, tyloses are formed Sheathing.— The structural covering, usually of boards or when walls of living cells surrounding vessels extend fiberboards, placed over exterior studding or rafters of into the vessels. They are sometimes formed in a structure. softwoods in a similar manner by the extension of Softwoods.—Generally, the botanical group of trees that cell walls into resin-passage cavities. bear cones and in most cases have needlelike or scale- Veneer.—A thin layer or sheet of wood cut on a veneer like leaves; also the wood produced by such trees. The machine. term has no reference to the actual hardness of the Rotary-cut veneer.—Veneer cut in a lathe which rotates wood. a log or bolt, chucked in the center, against a knife. Specific gravity.—The radio of the weight of a body to Sawed veneer.—Veneer produced by sawing. the weight of an equal volume of water at 4° C. or Sliced veneer.—Veneer that is sliced off a log, bolt, or other specified temperature. flitch with a knife. Springwood.— The portion of the annual growth ring that Vertical grain.—(See Grain.) is formed during the early part of the season’s growth. Vessels.—Wood cells of comparatively large diameter In most softwoods and in ring-porous hardwoods, it that have open ends and are set one above the other is less dense and weaker mechanically than so as to form continuous tubes. The openings of the summerwood. vessels on the surface of a piece of wood are usually Stain.— A discoloration in wood that may be caused by referred to as pores. such diverse agencies as micro-organisms, metal, or chemicals. The term also applies to materials used Virgin growth.—The original growth of mature trees. to color wood. Wane.—Bark or lack of wood from any cause on the Strength.— The term in its broader sense includes all the edge or corner of a piece of lumber. properties of wood that enable it to resist different Warp.— Any variation from a true or plane surface. forces or loads. In its more restricted sense, strength Warp includes bow, crook, cup, and twist, or any may apply to any one of the mechanical properties, combination thereof. in which event the name of the property under con- Weathering.— The mechanical or chemical disintegration sideration should be stated. thus: strength in com- and discoloration of the surface of wood that is pression parallel to grain, strength in bending, hard- caused by exposure to light, the action of dust and ness, and so on. sand carried by winds, and the alternate shrinking Stess.—Force per unit of area. and swelling of the surface fibers with the continual Stud.—One of a series of slender wood structural members variation in moisture content brought by changes in used as supporting elements in walls and partitions. the weather. Weathering does not include decay. Summerwood.—The portion of the annual growth ring that is formed after the springwood formation has Wood substance.—The solid material of which wood is ceased. In most softwoods and in ring-porous hard- composed. It usually refers to the extractive-free woods, it is denser and stronger mechanically than solid substance of which the cell walls are composed, springwood. but this is not always true. There is no wide varia- Tangential.— Strictly, coincident with a tangent at the tion in chemical composition or specific gravity circumference of a tree or log, or parallel to such a between the mood substance of various species; the tangent. In practice, however, it often means characteristic differences of species are largely due to roughly coincident with a growth ring. A tangential differences in infiltrated materials and variations in section is a longitudinal section through a tree or relative amounts of cell walls and cell cavities. limb and is perpendicular to a radius. Flat-grained Workability.— The degree of ease and smoothness of cut and plainsawed lumber is sawed tengentially. obtainable with hand or machine tools.

36