WOOD ANATOMY
INSTRUCTIONS FOR LABORATORY
WORK
KATARINA ČUFAR, MARTIN ZUPANČIČ
University of Ljubljana
Biotechnical Faculty
Department of Wood Science and Technology
Publisher
Department of Wood Science and Technology, Biotechnical Faculty, Rožna dolina, Cesta VIII/34,
Ljubljana, Slovenia
The publishing of “Wood Anatomy - Instructions for Laboratory Work”, a textbook by Katarina Čufar and Martin
Zupančič, intended to be used for courses in “Wood Anatomy” and “Wood Structure” (university study programme
Wood Science and Technology, higher professional study Technologies of Wood and Fibre Composites, university
and higher professional study programmes of Forestry and Renewable Forest Resources), is based on the decision
of the Dean of the Biotechnical Faculty Prof. Dr. Franc Štampar, dated 15 June 2009
CIP – Kataložni zapis o publikaciji
Narodna in Univerzitetna knjižnica, Ljubljana
674.03(075.8)(076)
630*81(075.8)(076)
ČUFAR, Katarina
Wood Anatomy - Instructions for Laboratory Work [text, illustrations and photos] Katarina Čufar, Martin
Zupančič; [translation Katarina Čufar, Maks Merela] – Ljubljana: Department of Wood Science and Technology,
Biotechnical Faculty, 2009
ISBN 978-961-6144-27-8
1. Zupančič, Martin,1962245920256
WOOD ANATOMY - INSTRUCTIONS FOR LABORATORY WORK
Authors
Katarina ČUFAR, Martin ZUPANČIČ
Reviewer
Prof. Dr. Željko Gorišek
Editor
Katarina Čufar
Cover page
Martin Zupančič, Luka Krže
Translation
Katarina Čufar, Maks Merela
English language editing
Martin Cregeen
Cover page photo
Cross section of a pine stem by Martin Zupančič
Print
Tiskarna Pleško d.o.o.
Barletova cesta 4
1115 Medvode
Printed 2009
100 copies
UDK: 674.03(075.8)(076)
GDK:630*81(075.8)(076)
ISBN-978-961-6144-27-8
WOOD ANATOMY
INSTRUCTIONS FOR LABORATORY
WORK
KATARINA ČUFAR, MARTIN ZUPANČIČ
University of Ljubljana
Biotechnical Faculty
Department of Wood Science and Technology
Ljubljana
2009
CONTENTS
CONTENTS ........................................................................................................................................ 4
Introduction and acknowledgements................................................................................................... 5
The objectives ..................................................................................................................................... 5
Exercise 1. The microscope ................................................................................................................ 9
Exercise 2. Three-Dimensional Structure of Wood .......................................................................... 12
Exercise 3. Microscopic structure of Scotch pine (Pinus sylvestris L.)............................................ 15
Exercise 4. Dichotomous microscopic key for identification of European softwoods ..................... 20
Exercise 5. Cells in the wood of silver fir (Abies alba Mill.) and beech (Fagus sylvatica L.) ......... 26
Exercise 6. The microscopic structure of beech (Fagus sylvatica L.) wood .................................... 27
Exercise 7. The microscopic structure of oak (Quercus sp.) wood................................................... 30
Exercise 8. The microscopic structure of ash (Fraxinus excelsior L.) wood.................................... 33
Exercise 9. The wood of Albizia adianthifolia from tropical Central Africa.................................... 35
Exercise 10. The wood of Manilkara fouilloyana from tropical Central Africa............................... 38
Exercise 11. Combination keys for microscopic identification of hardwoods ................................. 40
Exercise 12. European hardwoods .................................................................................................... 42
Exercise 13. Tissue of young tree stems ........................................................................................... 48
Exercise 14. Cambium, cambial zone ............................................................................................... 50
Exercise 15. The bark of fir (Abies alba Mill.) ................................................................................. 51
Exercise 16. The bark of lime (Tilia sp.)........................................................................................... 53
Exercise 17. The bark of beech (Fagus sylvatica L.)........................................................................ 55
Exercise 18. The anatomy of compression and tension wood .......................................................... 58
Exercise 19. Inorganic inclusions in wood and bark......................................................................... 60
Exercise 20. Macroscopic identification of European softwoods ..................................................... 62
Exercise 21. Macroscopic determination of European diffuse-porous hardwood ............................ 64
Exercise 22. Macroscopic determination of European semi-ring-porous hardwoods ...................... 67
Exercise 23. Macroscopic determination of European ring-porous hardwoods ............................... 68
Exercise 24. Special structures in wood............................................................................................ 70
Exercise 25. Wood defects ................................................................................................................ 73
Appendix 1. Hardwood identification - list of characters ................................................................ 79
Appendix 2. INTKEY (Richter and Dallwitz 2002) ......................................................................... 87
Literature: .......................................................................................................................................... 97
Katarina Čufar, Martin Zupančič, Wood Anatomy - Instructions for Laboratory Work
5
Introduction and acknowledgements
“Wood Anatomy - Instructions for Laboratory Work” has been written to make studying wood
structure and identification more interesting and effective. The exercises should be done after
each topic has been introduced by the teacher. The pictures should help to understand the
structure, function and properties of wood, cambium and bark tissues better. Students are
encouraged to prepare their own version of the material by completing it with their remarks,
text and drawings.
The version of this book in the Slovenian language has been in use for more than a decade. It
has been tested and improved by our associates and students. An increasing number of
international students and guests has increased the need to translate the materials into English.
Many colleagues and students have helped us to prepare this book. Special thanks are due to Dr.
Maks Merela for his help with translation, Luka Krže for technical editing, Dr. Jožica Gričar
and Peter Prislan for their valuable comments while testing the material, Prof. Dr. Željko
Gorišek for the revision, Martin Cregeen for language editing and all others who have helped us
to prepare the final version and to publish the material.
The objectives
Exercise 1. The microscope. The objective of this exercise is to review knowledge of the design
and function of a light microscope needed for work with microscopes in our microscopy
classroom and laboratories. It is important to know with which lenses and eyepieces the
microscope with which we are working is equipped. By observing millimetre paper, we can see
how much the objects are enlarged when we observe them with a particular combination of lens
and eyepiece. This can help us to estimate the dimensions of all the observed structures.
Exercise 2. Three-dimensional structure of wood. We observe objects under the microscope in
two-dimensional mode. Our brain must combine the two-dimensional images of cross, radial
and tangential sections into a three-dimensional image. Most of the structures can be seen in
different ways on all three anatomical sections. Many features can also be seen by the naked eye
or with the aid of a magnifying glass. These features are important for macroscopic
identification of wood and for estimating the properties of the wood. The aim of this exercise is
to observe a block of softwood, as well as diffuse porous and ring porous wood. The most
characteristic features of each of the anatomical sections should be drawn into the blank boxes.
Exercise 3. Microscopic structure of Scotch pine (Pinus sylvestris L.). Conifers and their wood
are evolutionarily old and primitive. Axial tracheids form over 90% of the wood tissue in
conifers. The other cells and tissues, making up less than 10% of the wood, are usually decisive
for wood identification. The aim of this exercise is to observe the wood of Scots pine in cross,
radial and tangential section. We start observation at the lowest magnification and then
subsequently increase it. We observe the object and make notes and answer the questions. The
exercise also presents how to draw the structure of the wood. The drawing of the radial section
shows different combinations of pits important for wood identification.
Exercise 4. Dichotomous microscopic key for identification of European softwoods (Grosser
1977). The exercise contains blank tables in which students can write which features can be
Katarina Čufar, Martin Zupančič, Wood Anatomy - Instructions for Laboratory Work
6
observed in different conifer woods. In the first step, students should learn how to use the
dichotomous identification key. First, read the first line of question (1). If the answer is positive,
go to question (2), if the answer is negative, read the second statement of question (1). A
positive answer to this statement leads to question (6). The procedure is repeated until the wood
species is finally identified. The completed table gives an overview of features characteristic of
important central European softwood species. Exercise 20 is similar, but the work there is based
on macroscopic features.
Exercise 5. Cells in the wood of silver fir (Abies alba Mill.) and beech (Fagus sylvatica L.). For
maceration of wood, we prepare particles of wood and treat them with chemicals (e.g., a
mixture of hydrogen peroxide and acetic acid). The chemicals dissolve the middle lamellae, and
the wood tissue is then decomposed into individual cells. Exercises 3 and 4 dealt with cells of
conifer woods. We must review which cells can be found in silver fir wood, then try to find
these cells on the microscopic slide. While drawing the cells, attention should be paid to the
forms and dimensions of the individual cells. The dimensions can be estimated with help of the
notes made in exercise 1. Cells that can be found in beech wood are listed in this exercise. The
cells of both species should be drawn under the same magnification.
Exercise 6. The microscopic structure of beech (Fagus sylvatica L.) wood. Beech is considered
to be an evolutionary primitive hardwood (dicotyledonous wood species). The cells of the wood
are listed. The aim of the exercise is to observe the wood in cross, radial and tangential section,
write the remarks and the required descriptions of the images and answer the questions.
Exercise 7. The microscopic structure of oak (Quercus sp.) wood. The wood of European oaks,
durmast and sessile oak (Quercus robur, Quercus petraea), is ring porous and evolutionarily
more developed than beech wood. The cells in the wood are listed. The aim of the exercise is to
observe the wood in cross, radial and tangential section, write the remarks and the required
descriptions of the images and answer the questions. Students should pay attention to the Latin
name of the observed wood species. Durmast and sessile oak cannot be exactly differentiated by
their wood structure.
Exercise 8. The microscopic structure of ash (Fraxinus excelsior L.) wood. Ash wood is ring
porous and evolutionarily highly developed and specialized. The cells in the wood are listed.
The aim of the exercise is to observe the wood in cross, radial and tangential section, write the
remarks and descriptions of the images and answer the questions.
Exercise 9. The wood of Albizia adianthifolia from tropical Central Africa. The wood of this
species is evolutionarily highly developed and specialized. It was selected because it has vessels
with very large diameters, paratracheal axial parenchyma, septate fibres, gum deposits in the
vessels, rhomboidal crystals in the chambered cells, and non-distinct growth ring boundaries.
Many of these features are rare in the wood of European species. The wood has a similar
density as the wood of European black alder (Alnus glutinosa). The aim of the exercise is to
observe the wood in cross, radial and tangential section, write the remarks and descriptions of
the images and answer the questions.
Exercise 10. The wood of Manilkara fouilloyana from tropical Central Africa. The density of
the wood often exceeds 1000 kg/m3. None of the commercial Central European wood species
has such a high density. The heartwood is dark brown to red-brown. The aim of the exercise is
to observe the wood in cross, radial and tangential section, write the remarks and descriptions of
the images and answer the questions.
Exercise 11. The combination keys for microscopic identification of hardwoods. The aim of the
exercise is to use one of the microscopic keys for hardwood identification, such as Brazier and
Franklin (1961) (Appendix 1), the IAWA list of microscopic features for hardwood
Katarina Čufar, Martin Zupančič, Wood Anatomy - Instructions for Laboratory Work
12
Exercise 2. Three-Dimensional Structure of Wood
Observe the samples of softwood, and diffuse-porous and ring-porous hardwood. Find annual
rings (syn. tree-rings, growth rings) and tree-ring boundaries, early- and late-wood, rays, resin
canals and vessels. On the picture below mark cross (C), radial (R) and tangential (T) sections
and mark how you should cut the sample to obtain an oriented cube of wood.
Katarina Čufar, Martin Zupančič, Wood Anatomy - Instructions for Laboratory Work
13
In the blank squares below draw the features that can be seen on C, R and T planes of the cube
of a softwood, and semi-porous and ring-porous hardwood. The sample must be oriented. The
pictures of three-dimensional structure of a hardwood and softwood below can help you.
Wood of fir
Softwood
Wood of beech
Katarina Čufar, Martin Zupančič, Wood Anatomy - Instructions for Laboratory Work
15
Exercise 3. Microscopic structure of Scotch pine (Pinus sylvestris L.)
Look at a microscopic slide of Scotch pine. Where are the cross (C), radial (R) and tangential
(T) sections? Observe each of the sections under the microscope. Find the microscopic features
and mark them on the photos.
On the images, mark tree-rings and tree-ring boundaries, axial resin canals, radial resin canals,
late-wood, transition from early- to late-wood, early-wood, radial tracheids arranged in radial
rows, bordered pits, axial and radial parenchyma cells, ray tracheids, axial tracheids,
fenestriform pits and define the type of rays (homocellular or heterocellular).
Cross section
Katarina Čufar, Martin Zupančič, Wood Anatomy - Instructions for Laboratory Work
Cross section
Radial section
Radial section
16