Series editors' preface - Wood Tools

In the walnut genus, Juglans, two important
microscopic features – crystals in longitudinal
parenchyma cells and reticulate thickenings,
(called gash-like pits) on some vessel walls –
provide a positive separation of North
American black walnut (Juglans nigra) from
European walnut (Juglans regia) (Figure
2.11).
Table 2.2 lists the features used for accurate
microscopic identification of hardwoods. These
Wood and wooden structures 73
body ray cells procumbent with over four rows of upright and/or square marginal cells
rays with procumbent, square and upright cells mixed throughout the ray
Sheath cells present
Tile cells present
Perforated ray cells present
Disjunctive ray parenchyma cell walls present
Ray per mm – ″ 4/mm or 4–12/mm or ≥ 12/mm
Wood ray-less
6 Storied structure
All rays storied
Low rays storied, high rays non-storied
Axial parenchyma and/or vessel elements storied
Fibres storied
Rays and/or axial elements irregularly storied
Number of ray tiers per axial mm
7 Secretory elements and cambial variants
Oil and/or mucilage cells associated with ray parenchyma or associated with axial parenchyma or present
among fibres
Intercellular canals
axial canals in long tangential lines or short tangential lines or diffuse
radial canals
intercellular canals of traumatic origin
Tubes or tubules present
Cambial variants – included concentric phloem or included diffuse phloem or other
8 Mineral inclusions
Prismatic crystals present – in upright and/or square ray cells or in procumbent ray cells or in radial
alignment in procumbent ray cells or in chambered upright and/or square ray cells or in non-chambered
axial parenchyma cells or in fibres
Druses present in ray parenchyma cells or in axial parenchyma cells or in fibres or in chambered cells
Other crystal types – raphides or acicular crystals or styloids and/or elongate crystals or crystals of other
shapes or crystal sand
Other diagnostic crystal features – more than one crystal of about the same size per cell or chamber or two
distinct sizes of crystal per cell or chamber or crystals in enlarged cells or crystals in tyloses or cystoliths
Silica
Silica bodies present – in ray cells or in axial parenchyma cells or in fibres
Vitreous silica present
Non-anatomical information
Geographical distribution
Specific gravity – low or medium or high
Heartwood colour
Odour
Heartwood fluorescence
Water and ethanol extracts – fluorescence and colour
Froth test
Chrome Azurol-s test
Burning splinter test
Source: Derived from Wheeler, Baas and Gasson (eds) (1989) IAWA list of microscopic features for hardwood identification, IAWA
Bulletin, 10 (3), 219–332
features are extensively described by Brazier
and Franklin (1961), Core et al. (1979), Grosser
(1977), Hoadley (1990), Panshin and deZeeuw
(1980), Phillips (1960), and Schweingruber
(1982, 1990). The quarterly bulletin of the
International Association of Wood Anatomists
(IAWA) provides excellent up-to-date information
on microscopic features, reviews of botanical
families, book reviews and articles on
wood anatomy.