Aggregate Ray A composite
of a number of small rays, some fibers and sometimes some vessels
together appearing under the lens as a single very broad ray.
Annual Growth The wood layer laid
down during any given year.
Annual Ring Growth ring.
Bird's Eye A figure on the tangential
surface caused by fiber distortion. There will be numerous small
rounded areas resembling a birds eye.
Brashness Condition of wood that results
in breaking quite suddenly and completely across the grain with
little splintering when the wood is bent slightly.
Compound Ray An unusually broad, large
ray commonly occurring in oak and Beech, etc. (obsolete)
Cross Grain Fiber alignment within
the wood is not parallel or strictly vertical in standing tree.
Interlocking of fibers make wood difficult to split.
Cross Section Surface of wood at right
angles to the run of the grain; a surface of the circular area
of the wood cylinder. Same as transverse section.
Diffuse-Porous Wood Porous wood in
which there is little on no variation in the pore size throughout
the annual ring.
Early Wood Portion of the growth
ring which is formed at the beginning of the growing season. Also
False Ring A band or streak of thick
walled cells appearing darker in color similar to the late wood
of the annual ring but which is proceeded and followed in the
growth ring by early wood cells. True band of late wood will occur
further out in the ring. There may be more than one false ring
within a true annual ring.
Fiber An elongated cell with pointed
ends and thick, or occasionally thin, walls occurring in the annual
Flat Sawn Tangential face shows on
the surface of the board. Same as plain-sawn
Fusiform Ray A spindle shaped ray,
quite broad in the middle, Containing a resin canal.
Grain of Wood Direction of arrangement
of wood cells when considered in relation to each other or as
Hardwood Porous wood produced by broad
leaved tree species.
Heart Wood Dead inner core of wood
in a tree usually of darker color.
Late Wood Portions of the annual ring
produced during the later part of the growing season. Also summer
Longitudinal Parenchyma Cells, the
long axis of which is parallel with that Parenchyma of the vessels
and tracheids. Usually forms distinguishing patterns within the
growth ring which are visible on the cross section. These cells
contain protoplasm and are thin walled, storing manufactured food.
Also axial parenchyma.
Longitudinal Resin Canal with long
axis of opening in alignment with Resin Canal long axis of wood
cells. Cross section of opening seen on the transverse surface.
Lumen The cavity of a cell. That place
where living contents have been or still are present.
Non-porous Wood Contains no vessels
or pores. These are the conifers or soft woods.
Parenchyma Short, thin walled cells
containing living contents in sapwood, storing and distributing
manufactured foods, particularly carbohydrates. Parenchyma is
dead but contains stored food.
Pitch Pocket Opening in coniferous
woods larger than a resin duct usually at growth increment boundaries
which contain or has contained resin. Usually lens shaped.
Pitch Streak Resin-soaked patches
of cells in coniferous woods.
Pitch Fleck Small areas of wound tissue
darker or lighter in color than surrounding tissue. Wounding of
the cambium by the larvae of small flies of genus Agromyza causes
wound tissue formation or parenchymatous cells which occlude the
Plain sawn Same as flat sawn.
Pore Cross section of a vessel as
it is observed on the transverse section of the wood of broad
Porous Wood Wood containing pores
or vessels. Same as hard wood. Produced by broad leaved species.
Quarter Sawn Boards sawn along the
radial surface of a split log or cant from a log so that long
axis of rays are exposed on surface of wood. Same as edge grained.
Radial Section Same as quarter section,
or surface; section parallel with long axis of rays, at right
angles to growth rings.
Ray Fleck Portion of the ray as it
appears on the radial surface.
Resin Canal A tube-like intercellular
space, in some coniferous woods, sheathed by secreting cells (epithelium)
bearing resin in the sapwood. Epithelial cells are dead in heart
wood. Resin usually fills the intercellular space.
Resin Tracheid Tracheid containing
deposits of resinous materials.
Ring Porous Wood Porous wood in which
pores are formed in a distinct, conspicuous band or row at the
beginning of the annual ring. Early wood pores are usually much
larger than the late wood pores.
Ring Shake A rupture in the wood which
occurs between the annual rings. Occasionally shake may occur
with in the annual rings.
Ripple Marks Striations across the
grain on the tangential surface of the wood, caused by the storied
arrangement of the rays or wood elements forming alternating streaks
of light absorbing and light reflecting bands.
Sapwood Outer portion of a woody stem,
usually lighter color than heartwood and containing living parenchyma
Semi-Diffuse Intermediate between
diffuse porous and ring porous wood Porous Wood but larger early
wood pores fail to form a distinct ring or band at the beginning
of the annual ring.
Simple Ray Small wood ray usually
a single cell in width as viewed in end section on the tangential
Soft Wood Wood of the coniferous tree
species. The wood itself is not always soft.
Specific Gravity The avendry weight
of a block of wood divided by the of Wood weight of the water
displaced by the wood at a given moisture content.
Spiral Grain Fibers are aligned helically
around the stem.
Straight Grained Fiber alignment is
parallel and vertical in the standing tree.
Tangential Section Section cut along
the grain at right angles to the rays.
Texture of Wood Size and number of
cells, proportions of large and small cells and number of rays
influence texture. Small diameter and numerous cells in a ring
usually form a fine textured wood.
Tracheid Lignified elongated cells.
Forming the main wood mass. Cell wall contains bordered pits and
forms a bluntly tapering or rounded edge.
Transverse Resin Canal Extends across
the grain and included within fusiform rays.
Traumatic Resin Canal Resin canal
assumed to originate as a result of an injury, usually occurring
in peripheral rows.
Tyloses Sac-like structures sometimes
developed in a vessel through the proliferation of the protoplast
of a parenchyma cell through the pit pairs.
Unisereate Ray Ray consisting of a
single row of cells as seen on the tangential surface.
Vessel A tube-like structure in porous
woods formed from the fusion of the cells in a longitudinal row
through the partial or complete disappearance of the cross walls.