Biermann Ch. Handbook of Pulping and Papermaking

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554 26. SOFTWOOD ANATOMY

species as southern pine and lumber that is pro-

duced from longleaf and slash pine species as

longleaf pine if conforming to the growth—ring

and latewood requirements. The lumber that is

classified as longleaf in domestic trade is known

also as pitch pine in the export trade. Three

southern

pines,

pitch, pond, and Virginia pine, are

designated in published grading rules as "minor

species," to distinguish them from the four princi-

pal species. Southern pine lumber comes mainly

from the Southern and South Atlantic States: from

North Carolina to Arkansas and Louisiana.

Uses. Longleaf and slash pines are classed as

heavy, strong,

stiff,

hard, and moderately high in

shock resistance. Shortleaf and loblolly pines are

usually somewhat lighter in weight than

longleaf.

All the southern pines have moderately large

shrinkage but are stable when properly seasoned.

The pith has been used to distinguish

longleaf,

shortleaf,

and loblolly pines (Koehler, 1917). To

obtain heavy, strong wood of the southern pines

for structural purposes, a density rule has been

written that specifies certain visual characteristics

for structural timbers.

Dense southern pine is used extensively in

construction of factories, warehouses, bridges,

trestles, and docks in the form of stringers, beams,

posts,

joists, piles, and plywood. Lumber of

lower density and strength finds many uses for

building material, such as interior finish, sheath-

ing, subflooring, and joists, and for boxes, pallets,

and crates. Southern pine is also used for tight

and slack cooperage. When used for railroad ties,

piles,

poles, and mine timbers, it is usually treated

with preservatives.

The southern pines are widely used in pulp

and paper products. They compete with

Douglas—fir for most linerboard and packaging

papers where high strength is required. Like

Douglas—fir, they form coarse papers.

Color. The wood of the various southern

pines is quite similar in appearance. The sapwood

is yellowish white and is usually wide in second-

growth stands. The heartwood is reddish or

orangish brown and begins to form when the tree

is about 20 years old. In old, slow—growth trees,

sapwood may be only 1 to 2 in. wide.

Macroscopic structure. The wood has an

abrupt latewood transition with a variable width

latewood. Resin canals are scattered throughout

the growth ring and are small for pine; the open-

ings are rarely visible without a lens (visible to the

unaided eye sometimes in longleaf pine). Non-

fusiform rays are fine and distinct with a lens.

Pitch,

pond,

and

Virginia

pines

These three species are the "minor" southern

pines in the southern pine grading rules; see the

previous entry for their structures. Pitch pine

(Pinus rigida) grows from Maine along the moun-

tains to eastern Tennessee and northern Georgia.

The heartwood is brownish red and resinous; the

sapwood is thick and light yellow. The wood of

pitch pine is medium heavy to heavy, medium

strong, medium

stiff,

medium hard, and medium

high in shock resistance. Its shrinkage is medium

small to medium large. It is used for lumber,

fuel, and pulpwood.

Pond pine

{Pinus serotina)

grows in the coast

region from New Jersey to Florida. It occurs in

small groups or singly, mixed with other pines on

low flats. The wood is heavy, coarse—grained,

and resinous, with dark, orange—colored heart-

wood and thick, pale yellow sapwood. Shrinkage

is moderately large. The wood is moderately

strong,

stiff,

medium hard, and medium high in

shock resistance. It is used for construction,

railway ties, posts, and poles.

Virginia pine (Pinus virginiana), known also

as Jersey pine and scrub pine, grows from New

Jersey and Virginia throughout the Appalachian

region to Georgia and the Ohio Valley. The

heartwood is orange and the sapwood nearly white

and relatively thick. The wood is rated moderate-

ly in weight, strength, hardness, and stiffiiess. It

has moderately large shrinkage and high shock

resistance. It is used for lumber, railroad ties,

mine props, pulpwood, and fuel.

Jack pine (Fig. 26-16)

Jack pine (Pinus banksiana), sometimes

known as scrub pine, gray pine, or black pine in

the U.S., grows naturally in the Lake States and in

a few scattered areas in New England and north-

ern New York. In lumber, jack pine is not sepa-

rated from the other pines with which it grows,

including red pine and eastern white pine.

Uses. It is moderately light in weight,

moderately low in bending strength and compres-

ANATOMY OF SOFTWOOD SPECIES 555

Fig. 26-16. Jack pine

(Pinus banksiana) (50

x).

sive strength, moderately low in shock resistance,

and low in stiffness. It also has moderately small

shrinkage. Lumber from jack pine is generally

knotty. Jack pine is used for pulpwood, box

lumber, pallets, and fuel. Less important uses

include railroad tie, mine timber, slack cooper-

age,

poles, and posts.

Color. The sapwood of jack pine is nearly

white; the heartwood is light brown to orange.

The sapwood may make up 50% or more of the

volume of a tree. The wood has a rather coarse

texture and is somewhat resinous.

Lodgepole pine (Figs. 26-17 and 26-18)

Lodgepole pine (Pinus contorta), also known

as knotty pine, black pine, spruce pine, and jack

pine,

grows in the Rocky Mountain and Pacific

coast regions as far northward as Alaska. Har-

vesting occurs largely from the central Rocky

Mountain States; other producing regions are

Idaho, Montana, Oregon, and Washington.

Uses. The wood is generally straight grained

with narrow growth rings (20—30/in.). The wood

is moderately light in weight, fairly easy to work.

and has moderately large shrinkage. Lodgepole

pine rates as moderately low in strength, moder-

ately soft, moderately

stiff,

and moderately low in

shock resistance. It is used for lumber, mine

timbers, railroad ties, and poles. Less important

uses include posts and fuel. Other uses include

for framing, siding, finish, and flooring.

Color. The heartwood of lodgepole pine

varies from light yellow to light yellow—brown

and is only slightly darker than the sapwood;

often it is not clearly defined from the sapwood.

The sapwood is yellow or nearly white, usually 1

in. wide, but sometimes over 2 in. wide.

Macroscopic features. The wood has a fairly

abrupt transition to the narrow latewood. The

resin ducts are small and numerous. They are not

distinctly visible without a lens, although the sap

is sometimes visible. The rays are very fine,

except for the fusiform rays, which are quite

distinct under a lens. The tangential surface is

slightly dimpled. The wood has a distinct resinous

odor that is stronger than that of most pines.

Similar woods. Ponderosa pine resembles

lodgepole pine, but ponderosa pine has darker and

556 26. SOFTWOOD ANATOMY

more distinct heartwood, wider sapwood, larger

growth rings, larger resin

ducts,

and rarely has the

pronounced dimpled surface (t) of lodgepole pine.

Ponderosapine (Figs. 26-19 and 26-20)

Ponderosa pine

{Pinus

ponderosa) is known

as ponderosa pine, western soft pine, western

pine,

California white pine, bull pine, and black

jack. Jeffrey pine (P. jejfreyi), which grows in

close association with ponderosa pine in California

and Oregon, is usually marketed with ponderosa

pine and sold under that name. Major producing

areas are in Oregon, Washington, and California;

moderate amounts come from Idaho and Montana;

and small amounts come from Wyoming and the

Black Hills of South Dakota.

Uses. The wood of the outer portions of

ponderosa pine of sawtimber size is generally

moderately light in weight, moderately low in

strength, moderately soft, moderately

stiff,

and

moderately low in shock resistance, ft is generally

straight grained and has moderately small shrink-

age,

ft is quite uniform in texture and has little

tendency to warp and twist.

Fig. 26-17. Pinus contorta.

Fig. 26-18. Lodgepole pine

{Pinus contorta) (50

x).

ANATOMY OF SOFTWOOD SPECDSS 557

Ponderosa pine is used mainly for lumber,

particleboard, and pulp chips and to a lesser extent

for piles, poles, posts, mine timbers, veneer, and

ties.

The clear wood goes into sash, doors,

blinds, moldings, paneling, mantels, trim, and

built—in cases and cabinets. Knotty pine is also

used in paneling. Lower grade lumber is used for

boxes and crates.

Color. Ponderosa pine belongs to the yellow

pine group. Much of the wood, however, is

somewhat similar to the white pines in appearance

and properties. The heartwood is light reddish or

orangish brown and clearly defined from the

sapwood. The wide sapwood (2.5—4 in.) is

nearly white to pale yellow.

Macroscopic structure. The transition to

latewood is abrupt as in the southern

pines,

but the

latewood bands are narrow though variable. The

tangential surface is often dimpled as in lodgepole

pine,

but in the latter they are small and more

abundant. The numerous resin canals are larger

than those of lodgepole pine. The heartwood of

lodgepole pine is lighter in color than that of

ponderosa pine.

Fig. 26-19. Pinus ponderosa.

Fig. 26-20. Ponderosa pine (Pinusponderosa) (50x).

558 26. SOFTWOOD ANATOMY

Microscopic features, Ponderosa pine may

be distinguished from Jack pine because the

dentations of the ray tracheids are more

pronounced than those of Jack pine.

Red pine

Red pine (Pinus

resinosa)

is frequently called

Norway pine. It is occasionally known as hard

pine and pitch pine. This species grows in the

New England States, New York, Pennsylvania,

and the Lake States. In the past, lumber from red

pine has been marketed with white pine without

distinction as to species.

Uses. Red pine is moderately heavy, moder-

ately strong and

stiff,

moderately soft, and moder-

ately high in shock resistance. The wood is the

lightest of the hard pines east of the Mississippi

River. It is generally straight grained, not so

uniform in texture as eastern white pine, and

somewhat resinous. The wood has moderately

large shrinkage but is not difficult to dry and stays

in place well when seasoned.

Red pine is used principally for lumber and

to a lesser extent for piles, poles, cabin logs,

posts,

pulpwood, and fuel. The wood is used for

many of

the

purposes for which eastern white pine

is used. It goes mostly into building construction,

siding, flooring, sash, doors, blinds, general

millwork, and boxes, pallets, and crates.

Color. The heartwood of red pine varies

from pale red to reddish brown. The sapwood is

nearly white with a yellowish tinge, and is gener-

ally from 2 to 4 inches wide. The wood resem-

bles the lighter weight wood of southern pine.

Latewood is distinct in the growth rings.

Macroscopic structure. The wood has a

somewhat abrupt transition

latewood. The resin

ducts tend to be concentrated in the outer half of

growth rings with openings that are not visible

without a lens. Nonfusiform rays are fine. The

annual rings are fairly wide.

Similar woods. Red pine resembles the

southern pines; it is quickly separated by its

fenestriform pitting in the cross—fields.

Spruce

pine

Spruce pine (Pinus glabra), also known as

cedar pine, poor pine, Walter pine, and bottom

white pine, grows on low moist lands of the

coastal regions of southeastern South Carolina,

Georgia, Alabama, Mississippi, and Louisiana,

and northern and northwestern Florida. The

heartwood is light brown, and the wide sapwood

zone is nearly white.

Uses. Spruce pine wood is lower in most

strength values than the major southern pines. It

compares favorably with white fir in bending

properties, in crushing strength perpendicular and

parallel to the grain, and in hardness. It is similar

to the denser species such as coast Douglas—fir

and loblolly pine in shear parallel to the grain.

The principal uses of spruce pine were

locally for lumber, and for pulpwood and

fuelwood. The lumber, which is classified as one

the

minor southern pine species, reportedly was

used for sash, doors, and interior finish because of

its lower specific gravity and less marked distinc-

tion between earlywood and latewood. It has

qualified for use in plywood.

Sugar pine (Fig. 26-21)

Sugar pine (Pinus lambertiana) is sometimes

called California sugar pine. Most of the sugar

pine lumber is produced in California and the

remainder in southwestern Oregon.

Uses. The wood is straight grained, fairly

uniform in texture, and easy to work with tools.

It has very small shrinkage, is readily seasoned

without warping or checking, and stays in place

well. This species is light in weight, moderately

low in strength, moderately soft, low in shock

resistance, and low in stiffness.

Sugar pine is used almost entirely for lumber

products. The largest amounts are used in crates,

sash, doors, frames, blinds, general millwork,

building construction, and foundry patterns. Like

eastern white pine, sugar pine is suitable for use in

nearly every part of a house because of the ease

with which it can be cut, its ability to stay in

place, and its good nailing properties.

Color. The heartwood of sugar pine is buff

or light brown, sometimes tinged with red; it is

lighter than that of P. strobus or P. monticola.

The sapwood is creamy white.

Macrostructure. Resin canals are abundant

and commonly stain the longitudinal surfaces.

Transition from earlywood to latewood is gradual,

and the growth rings are not prominent on

flatsawn surfaces. The wood is coarse textured.

Fig.

26-21.

Pinus lambertiana.

ANATOMY OF SOFTWOOD SPECIES 559

Microscopic structure. The intertracheid

pitting may be biseriate for four or more consecu-

tive pit pairs in the first part of the earlywood.

Eastern

white

pine (Fig. 26-22)

Eastern white pine (Pinus strobus) grows

from Maine to northern Georgia and in the Lake

States. It is also known as white pine, northern

white pine, Weymouth pine, and soft

pine.

About

50%

of the lumber is produced in the New Eng-

land States, about 30% in the Lake States, and

most of the remainder in the Middle Atlantic and

South Atlantic States.

Uses. It is easily kiln—dried, has small

shrinkage, and ranks high in stability. The wood

has comparatively uniform texture and is straight

grained. It is also easy to work and can be readily

glued. It is light in weight, moderately soft,

moderately low in strength, and low in resistance

to shock. Almost all eastern white pine is con-

verted into lumber; a large proportion, which is

mostly second-growth knotty lumber of the lower

grades, goes into container and packaging applica-

tions.

High-grade lumber goes into patterns for

Fig. 26-22. Eastern white pine

(Pinus strobus)

(50x).

560

26.

SOFTWOOD ANATOMY

castings. Other uses are sash, door, furniture,

trim, knotty paneling, finish, caskets and burial

boxes,

shade and map rollers, toys, and dairy and

poultry supplies.

Color. The heartwood of eastern white pine

is light brown, often with a reddish

tinge.

It turns

considerably darker on exposure.

Macrostructure. The wood has a gradual

transition to latewood. The latewood is narrow

and darker than the earlywood.

Western

white

pine (Figs. 26-23 and 26-24)

Western white pine

{Pinus monticola)

is also

known as Idaho white pine or white pine. About

four—fifths of the cut comes from Idaho with the

remainder mostly from Washington; small

amounts are cut in Montana and Oregon.

Uses. The wood is straight grained, easy to

work, easily kiln—dried, and stable after season-

ing. This species is moderately light in weight,

moderately low in strength, moderately soft,

moderately

stiff,

moderately low in shock resis-

tance, and has moderately large shrinkage.

Fig. 26-23. Pinus monticola.

Fig. 26-24. Western white pine

(Pinus monticola) (50

x).

ANATOMY OF SOFTWOOD SPECIES

561

Practically all western white pine is sawed

into lumber and used for building construction,

matches, boxes, patterns, and millwork products,

such as sash, frames, doors, and blinds. In

construction, boards of the lower grades are used

for sheathing, knotty paneling, subflooring, and

roof strips. High—grade material is made into

siding of various kinds, exterior and interior trim,

and finish. It has practically the same uses as

eastern white pine and sugar pine.

Color. Heartwood of western white pine is

cream colored to light reddish brown and darkens

on exposure. The sapwood is yellowish white and

generally from 1 to 2 (occasionally 3) in. wide.

Macroscopic

features. The openings of the

resin canals are plainly visible with a lens, and

sometimes without a lens. The canals are abun-

dant throughout the growth ring. The rays are

mostly fine, although the fusiform rays are more

pronounced. The annual rings are distinct and

moderately wide. The wood has gradual transition

to the narrow latewood.

Similar woods. It is separated from sugar

pine by the larger resin canals in sugar pine and

microscopic features. It is difficult to separate

from P. strobus. Limber pine is very similar, but

it is usually heavier.

Scotch

pine

Scotch pine (Pinus sylvestris) is native to

Europe and Asia, but now grows in southeastern

Canada and northeastern U.S. A British term for

construction lumber from this species (or soft-

woods in general) is deal.

PSEUDOTSUGA

Douglas—fir

(Figs.

26-25 and 26-26)

Douglas—fir

(Pseudotsuga

menziesii and var.

glauca) is also known locally as red fir, Douglas-

spruce, and yellow fir. (The older literature refers

to it as P. taxifola.) There are two varieties, the

coastal and the mountain types. The range of

Douglas—fir extends from the Rocky Mountains to

the Pacific coast and from Mexico to central

British Columbia. The Douglas—fir production

comes from Oregon, Washington, California, and

the Rocky Mountain States.

Uses. The wood of Douglas—fir varies

widely in weight and strength. When structural

lumber of high strength is required, selection can

be improved by applying the density rule, which

has latewood percentage and growth rate criteria.

Douglas—fir is used mostly for building and

construction purposes in the form of lumber,

timbers, piling, and plywood. Considerable

quantities go into railroad ties, cooperage stock,

mine timbers, poles, and fencing. Douglas—fir

lumber is used in the manufacture of various

products, including sash, doors, general millwork,

railroad—car construction, boxes, pallets, and

crates.

Small amounts are used for flooring,

furniture, ship and boat construction, wood pipe,

and tanks. Douglas—fir is widely used in pulp

and paper products, especially in linerboard and

sack

papers,

where it competes with southern pine,

where high strength is required. It forms coarse

papers and obtaining good formation is difficult.

Color. Sapwood of Douglas—fir

narrow in

old—growth trees but may be as much as 3 inches

wide in second—growth trees of commercial size.

Young trees of moderate to rapid growth have

reddish heartwood and are called red fir. Very

narrow—ringed wood of old trees may be yellow-

ish brown and is known on the market as yellow

fir.

Macroscopic

structure.

The resin canals may

form tangential rows of 2 to 20 (traumatic resin

canals would have much longer tangential rows).

The resin canals are much smaller than those of

the pines, and Douglas—fir normally has a distinc-

tive odor. The bark of Douglas—fir (Fig. 2-1,

left) has layers that distinguish it from other

species with which it may be confused.

562 26. SOFTWOOD ANATOMY

Microscopic structure. Spiral thickening

(yew has this but no resin canals) in the tracheids

is a characteristic feature of Douglas—fir. Mar-

ginal longitudinal parenchyma are sometimes

observed.

PICEA

With the exception of sitka spruce, the wood

of spruces are not readily assigned to individual

species without additional information since their

anatomies are very similar. Engelmann spruce,

however, tends to have an abrupt transition to

latewood since it grows at high elevation in the

Rocky Mountains.

Eastern spruce

The term "eastern spruce" includes three

species, red (Picea

rubens),

white (P. glauca), and

black (P. mariana) (Fig. 26-27). White spruce

and black spruce mainly grow in the Lake States

and New England, and red spruce in New England

and the Appalachian Mountains. All three species

have about the same properties, and in commerce

no distinction is made between them.

Fig. 26-25. Pseudotsugamenziesii.

Fig. 26-26. Douglas-fir (Pseudotsugamenziesii) (50x).

Uses,

The

wood dries easily

and is

stable

after drying,

moderately light

weight

and

easily worked,

has

moderate shrinkage,

and is

moderately strong,

stiff,

tough,

and

hard.

The

largest

use of

eastern spruce

is for

pulpwood.

is also used

for

framing material, general mill-

work, boxes

and

crates, ladder rails, scaffold

planks,

and

piano sounding boards. Eastern

spruce

sold with balsam

fir as

spruce—fir,

but

the latter lacks resin canals. Balsam

fir is

heavier

than eastern spruce when

wet due to its

higher

moisture content,

but is

lighter when

dry.

Color.

The

wood

light

color,

and

there

is little difference between

the

heartwood

and

sapwood colors.

The

high luster

eastern spruce

is used

help distinguish

from northern white

pine.

Macroscopic structure.

The

transition

to the

very narrow latewood

gradual.

The

resin canals

are small

and

appear

white dots

[in the

cross

section (x)].

The

rays

are

visible with

lens

ANATOMY

SOFTWOOD SPECIES

563

wet surfaces

(x).

Fusiform rays occur randomly

and

are

widely spaced.

Sitka spruce (Figs. 26-28

and

26-29)

Sitka spruce {Picea sitchensis)

is a

tree

large size growing along

the

Pacific coast from

California to Alaska. Local names include yellow

spruce, tideland spruce, western spruce,

and

silver

spruce. About

2/3 of

Sitka spruce lumber comes

from Washington

and 1/3

from Oregon.

Uses.

It is

moderately light

weight,

moderately

low in

bending

and

compressive

strength, moderately

stiff,

moderately soft,

and

moderately

low in

resistance

shock.

It has

moderately small shrinkage.

On the

basis

weight,

rates high

strength properties

and can

be obtained

clear, straight—grained pieces.

Sitka spruce

used principally

for

lumber,

pulpwood,

and

cooperage.

ranks high

as a

pulpwood because

of its

long, strong fibers

and

ease

pulping. Boxes

and

crates account

for a

Fig. 26-27, Black spruce (Picea mariana) (50

x).