q Gymnosperm Wood2.02.0 GYMNOSPERM WOOD IDENTIFICATION A component of MIAMI UNIVERSITY DENDROLOGY EXPERT SYSTEM CREATED BY DR. ROGER D. MEICENHEIMERq CXAttdataWood Reflects Light Wood Appears Dull  Bitter Taste  Spicy Taste  Indistinct Growth Rings1Little difference between tracheid cell wall thickness in the summer wood of one growth ring and the spring wood of the next adjacent growth ring.End walls nodular25gAbundant simple pits in end walls of ray parenchyma give them a nodular appearance in radial section.GWH5.jpg Sweet Taste Golden Heartwood See image GWHFIG.jpgOrangish Heartwood See image GWHFIG.jpgDistinctive Smell Wood has some odor to it that you may or may not associate with something. Be sure that what you are smelling is associated with the wood, rather than decay organisms.Intermediate Texture Wood  Salty Taste Smell Resembles Raw Potatoes Wood Dimpled on Tangential Face  Hard Wood600 to 699 poundsVery Hard WoodGreater than 700 pounds Very Light Weight Wood"Less than 30 pounds per cubic foot Light Weight Wood31 to 40 pounds per cubic foot Heavy Weight Wood41 to 50 pounds per cubic foot Very Heavy Weight Wood%Greater than 50 pounds per cubic footWhitish YellowishGoldenOrangishPinkishGreenishReddishBrownishPurplishGrayishBlackishWhitish Heartwood See image GWHFIG.jpgGreyish Heartwood See image GWHFIG.jpgYellowish Heartwood See image GWHFIG.jpgReddish Heartwood See image GWHFIG.jpgPinkish Heartwood See image GWHFIG.jpgBrownish Heartwood See image GWHFIG.jpgBlackish Heartwood See image GWHFIG.jpgSmooth Texture Wood Rough Texture Wood Even Figured Wood Wood has a uniform appearance. GWHCOL.jpgUneven Figured Wood &Wood exhibits variation in appearance. GWHCOL.jpgRays Obscure to Unaided Eye See image AGHWOOD.jpgRays Distinct to Unaided Eye See image AGHWOOD.jpgVery Soft Wood Less than 400 pounds Soft Wood 400 to 499 pounds Medium Wood 500 to 599 poundsVery Light Weight Wood "Less than 25 pounds per cubic footLight Weight Wood 26 to 30 pounds per cubic footHeavy Weight Wood 31 to 34 pounds per cubic footVery Heavy Weight Wood %Greater than 35 pounds per cubic footGreasy or Oily Texture Wood Unpleasant Smell Makes you pull away or wrinkle your nose. Wood smelling this way should be examined for freshness since some wood decaying bacteria/fungi produce disagreeable odors & are nondiagnostic!Resinous Smell {Resembles "Pine Trees". Caused by volatile compounds associated with liquid resins in canals - so look for resin canals.Aromatic Smell Resembles "Pencils" or " Cedar Chests" Caused by volatile compounds sequestered in individual cells and cell walls - so look for presence of axial parenchyma.Purplish Heartwood See image GWHFIG.jpg "Abrupt SpringSummerwood transition3Very distinct boundary between thinner cell walls of spring wood tracheids and thicker cell walls of summer wood tracheids within one annual growth ring.GHW1.jpg "Gradual Sprg-Summr wood transition pGradual change in cell wall thickness between spring and summer wood tracheids within one annual growth ring.GHW1.jpgPits Alternate8lPortions of two or more pits overlap at one horizonal level along a tracheid in the alternate arrangement.GHW2.jpgUniseriate pits ;Single pit at any given horizontal level along a tracheid.GHW2.jpg>1-seriate, opposite pits9iTwo or more complete pits occupy a given horizontal level along a tracheid in the opposite arrangement.GHW2.jpgSmooth16#No obvious uneveness in cell walls. GWH4A.jpg!Spiral thickenings in spring wood11Periodic regions of thicker cell wall material, normally inclined at ca. 90 degrees to longitudinal axis of tracheid. Don't confuse with checking artifact oriented at 10-45 degrees.GHW2.jpg Present13Axial parenchyma can be observed in transverse, radial, and tangential sections. Do not include parenchyma associated with resin canals or wound healing in this character.GHW3.jpg => 5 cells/mm^2 in cross section14Assess the density of axial parenchyma in the transverse section of region in the wood that contains it. Most often axial parenchyma occurs in summer wood.GHW3.jpg Nodular end walls15Abundant simple pit pairs give the short end walls of axial parenchyma a nodular or beaded appearance as viewed in tangential longitudinal section.GHW3.jpgNotched borders50XIndividual pit borders appear flattened or notched instead of circular in radial view.GHW2.jpgTori extensions51=Strap-like extensions radiate from the torus in radial view.GHW2.jpgMinute dentations17RVery small projections of cell wall material extend into lumen of ray tracheids. GWH4B.jpgMedium dentations18TObvious tooth-like projections of cell wall material into lumens of ray tracheids. GWH4C.jpgReticulate dentations19cNumerous cell wall projections form an interconnected network within the lumens of ray tracheids. GWH4D.jpgHorizontal walls thin20Thin horizontal walls of ray parenchyma are thinner than vertical walls of adjacent axial tracheids as viewed in radial section.GWH5.jpgHorizontal walls unpitted21RHorizontal walls of ray parenchyma lack simple pits as viewed in radial section.GWH5.jpg!Horizontal walls w/ numerous pits22]Simple pits are abundant in horizontal walls of ray parenchyma as viewed in radial section.GWH5.jpg Indentures23LCorners of ray parenchyma exhibit depressions as viewed in radial section.GWH5.jpgWall corners thickened24dCorners of ray parenchyma are thicker than edges of the same cell as viewed in tangential section.GWH5.jpg> 30 cells high26cWood has more than two rays per mm that are higher than 30 cells as viewed in tangential section.GWH5.jpgCrystals27Cuboidal, octahedral, or rectangular crystals can be present in ray cells. Use of polarizing microscopy can help in locating these crystals.GWH5.jpg1-3 large windowlike, Pinoid28vLarge square or rectangular pits with little or no apparent borders. One to three pits nearly fill the cross field. GWH6A.jpg1-6 large Pinoid32Large square or elliptical pits with slight to obvious borders. At least some of the cross fields have more than three pits per field. Pits nearly fill the cross field. GWH6B.jpg Taxodioid31Widest part of pit aperture is about equal to diameter of pit chamber. Narrowest part of pit aperture is about equal to border width in the center of the pit. GWH6D.jpg Cupressoid30Widest part of pit aperture less than diameter of pit chamber. Narrowest part of pit aperture less than width of pit border in the center of pit. GWH6C.jpgPiceoid29Extremely small pits with narrowly elliptical apertures. Widest part of aperture extends slightly beyond pit chamber. Narrowest part of aperture less 1/3 size of the border at center. GWH6E.jpgVertical33Resin ducts running vertically within wood can be most easily observed end-on in transverse section, but can also be seen occasionally in longitudinal sections.GWH7.jpg Horizontal35Resin ducts running horizontally within the rays can be most easily seen in tangential section, but can be occasionally observed in transverse and radial longitudinal section as well.GWH7.jpgThick epithelial cell walls36Thick epithelial cell walls are similar in thickness to the cell walls of axial tracheids. Thin epithelial cell walls are thinner than the cell walls of axial tracheids.GWH7.jpg 5-6 epithelial cells/horzntl dct37Count the number of epithelial cell walls associated with resin ducts as viewed in tangential section. For accuracy in counting, make sure all epithelial cells are intact.GWH7.jpg"7-12 epithelial cells/ horzntl dct38Count the number of epithelial cells lining the horizontal resin ducts as viewed in tangential section. For accuracy in counting make sure all epithelial cells are intact.GWH7.jpgGreenish Heartwood See image GWHFIG.jpgL CXMenudataGymnosperm Woodss MICROSCOPIC WOOD CHARACTERISTICSmAssess using a light microscope to examine transverse (X), radial (R), and tangential (T) sections of wood. GWHSECT.jpg  sCOLOR OF FRESH HEARTWOODPertains to Heartwood (older, usually darker, central region of stem) Reflects differences in chemical composition. Air may darken the color. Nondiagnostic color may result from bacteria or fungi. HCOLOR.jpg :>=<{X?;@s MACROSCOPIC WOOD CHARACTERISTICSAssess these characters visually with the unaided eye, and by using the feel, smell, and taste of the wood. Many of these characteristics are best learned through comparative experience.   s WOOD TEXTUREPAssess by touch. Reflects size and distribution of various cells in the wood.A BN s WOOD FIGUREVisually assess the uniformity of wood appearance. Produced by relative arrangement of different cells and/or color in the wood. Sometimes confused with grain (orientation of tracheids). GWHCOL.jpgCDsDRY WOOD WEIGHTRelative weight of air dry wood. Reflects Sap/Heart and Spring/Summer Wood Ratios and Moisture Content. Increasing moisture increases weight.JKLMs WOOD LUSTERTilt radial surface of split wood to reflect light. Luster is proportional to size and density of ray and axial parenchyma in general. Care should be used if examining planed or sanded woodsTASTE OF FRESH HEARTWOODSince the human tongue's sensory organs are spatially segregated, taste wood by pressing a piece large enough to cover all sensory areas. Avoid splinters. GWHTASTE.jpg sRAY CHARACTERISTICSRays run radially within the stem and are typically lighter than surrounding axial tracheids. Assess cell types and pit details in radial sections containing complete rays. GWHSECT.jpgsAXIAL PARENCHYMA FEATURESAxial parenchyma cells are vertically elongated cells that contain cytoplasm, have simple pits, and appear rectangular in radial and tangential longitudinal section.GHW3.jpg`abs GROWTH RINGSvAssess relative cell wall thickness of tracheids in spring (early) and summer (late) wood in transverse (X) section.GHW1.jpgYZsGREEN WOOD WEIGHTsCOLOR OF FRESH SAPWOOD sssssssssRAY VISIBILITY TO UNAIDED EYEDistinct rays are visible with the unaided eye. Rays extend radially from center toward the outside and are typically lighter than the surrounding wood.Use transverse or tangential plane AGHWOOD.jpgEFs WOOD HARDNESSAssess by pressing surface with fingernail. Closely related to weight, but increasing moisture decreases hardness. Varies in transverse, radial, and tangential surfaces.GHIsSMELL OF FRESH HEARTWOODBest assessed by odor of freshly exposed heartwood. Distinct odors are due to volatile extraneous substances in the wood. Odors fade upon exposure to air.PRT sAXIAL TRACHEID FEATURESAxial tracheids are elongate parallel to stem axis. Assess the details of pit features and variations in cell wall thickness within axial tracheids viewed in radial section. GWHSECT.jpg\][cd_s RAY TRACHEID FEATURESRay tracheids occur along the margins of rays, have circular bordered pits, slanted end walls, and no cytoplasm. Assess details of cell wall thickening.GHW4.jpg^efgs RAY PARENCHYMA FEATURESRay parenchyma contain cytoplasm, have simple pits, and are rectangularly elongated in the radial plane. Assess details of cell walls and presence of cystals.GWH5.jpghijklnos TYPE OF CROSS-FIELD PITSAssess the number and shape of cross field pits, or pits occurring between individual axial tracheids and individual ray parenchyma cells. Use radial sections of spring wood.GWH6.jpgpqrstsRESIN DUCT CHARACTERISTICSWell defined canals or ducts that are lined with parenchymatous epithelial cells. Assess orientation of ducts; number and cell wall thickness of epithelial cells.GWH7.jpguwxyzsssssssssssssssssssssssssssssssssssssssssssss1Science and Technology of Wood. 1991. G. Tsoumis.