ArticlePDF Available
STUDIA UBB CHEMIA, LXVIII, 1, 2023 (p. 119-129)
(RECOMMENDED CITATION)
DOI:10.24193/subbchem.2023.1.09
©2023 STUDIA UBB CHEMIA. Published by Babeş-Bolyai University.
This work is licensed under a Creative Commons Attribution-
NonCommercial-NoDerivatives 4.0 International License.
RADIOCARBON DATING OF THE HISTORIC GRAND
BAOBAB OF MAHAJANGA, MADAGASCAR
Adrian PATRUTa, b*, Roxana T. PATRUTa,
Laszlo RAKOSYc, Ileana Andreea RATIUa,b, Pascal DANTHUd,
Jean-Michel LEONG POCK TSYe, Karl F. Von REDENf
ABSTRACT. The article reports the AMS (accelerator mass spectrometry)
radiocarbon investigation of the historic Grand Baobab of Mahajanga. The
largest African baobab of Madagascar exhibits a cluster structure, which
consists of 6 fused ordinary stems and of 3 small binding stems. Two samples
were collected from the largest stem and from a primary branch, out of which
several tiny segments were extracted and dated by radiocarbon. The oldest
dated sample segment had a radiocarbon date of 214 ± 17 BP, which
corresponds to a calibrated age of 265 ± 25 calendar years. The dating results
indicate that the Grand Baobab of Mahajanga is 275 ± 25 years old.
Keywords: AMS radiocarbon dating, Adansonia digitata, dendrochronology,
Madagascar, age determination, multiple stems.
INTRODUCTION
The Adansonia genus, which belongs to the Bombacoideae, a subfamily
of Malvaceae, consists of eight generally recognised species. One species
originates from mainland Africa, six are endemic to Madagascar, while another
a Babeş-Bolyai University, Faculty of Chemistry and Chemical Engineering, 11 Arany Janos,
RO-400028, Cluj-Napoca, Romania
b Babeş-Bolyai University, Raluca Ripan Institute for Research in Chemistry, 30 Fantanele,
RO-400294 Cluj-Napoca, Romania
c Babeş-Bolyai University, Faculty of Biology and Geology, 44 Republicii, RO-400015 Cluj-
Napoca, Romania
d Cirad, UPR HortSys, Montpellier, France
e Drfgrn-fofifa, Antananarivo, Madagascar
f NOSAMS Facility, Dept. of Geology & Geophysics, Woods Hole Oceanographic Institution,
Woods Hole, MA 02543, USA
* Corresponding author: apatrut@gmail.com
ADRIAN PATRUT, ROXANA T. PATRUT, LASZLO RAKOSY, ILEANA ANDREEA RATIU,
PASCAL DANTHU, JEAN-MICHEL LEONG POCK TSY, KARL F. VON REDEN
120
grows only in northern Australia. The African baobab (Adansonia digitata L.)
is certainly the best-known and widespread among these species. It is endemic
to the arid savanna of mainland Africa between the latitudes 16º N and 26º S.
The African baobab can also be found on several African islands and outside
Africa, in different areas throughout the tropics, where it has been introduced
[1-5].
In 2005, we started a complex research project for elucidating several
controversial aspects related to the architecture, growth and age of the African
baobab. This research relies on AMS radiocarbon dating of tiny wood samples
extracted from different areas of big baobabs [6-14]. According to the obtained
results, all superlative, i.e., very large and/or old baobabs, are practically multi-
stemmed and exhibit preferentially closed or open ring-shaped structures. The
oldest specimens were found to reach ages up to 2,500 years [11].
Since 2013 our investigations also include superlative individuals of
the three best-known species of Madagascar, i.e., Adansonia za Baill. (Za
baobab), Adansonia rubrostipa Jum. & H. Perrier (Fony baobab) and Adansonia
grandidieri Baill (Grandidier baobab) [15-20]; each species is represented by
over one million individuals. On the northwestern coast of Madagascar, between
Diego Suarez and Mahajanga, there are located several thousand African
baobabs. One specimen, namely the baobab of Mahajanga, is famous for its
very large dimensions [21].
Here we present the investigation and AMS radiocarbon dating results
of the historic African baobab of Mahajanga.
RESULTS AND DISCUSSION
The Grand Baobab of Mahajanga and its area. Mahajanga (formerly
French Majunga) is a city, an administrative district and important seaport
on the northwestern coast of Madagascar. It has a population of 250,000
inhabitants and is the capital city of the Boeny region. Mahajanga has a
tropical savanna climate with two distinct seasons, a rainy wet season (from
November to mid-April) and a sunny dry season (from mid-April to October).
Cyclons can occur during the wet season and may produce considerable
damage. The mean annual temperature is 26.3°C and the mean annual rainfall
is 1476 mm.
The Grand Baobab of Mahajanga (in French, “le gros baobab de
Majunga”) grows on the coast, at around 100 m from the sea. Today, the big
baobab is protected by a fence in the centre of a large traffic roundabout, where
two waterfront boulevards meet the main boulevard “Avenue of France”. The
lower trunk is painted to protect against pests and the surroundings of the tree
are concreted.
RADIOCARBON DATING OF THE HISTORIC GRAND BAOBAB OF MAHAJANGA, MADAGASCAR
121
The historic baobab is the symbol of the whole city, with people usually
sitting under it. It also appears on the emblem of Mahajanga.
In earlier times, the baobab was used as a place for announcing news
to the community and also as a meeting place. In the 19th century, the baobab
marked the site for public executions. According to tradition, every traveler
must walk around the baobab seven times to receive the blessing of the
Malagasy ancestors.
Two decades ago, the baobab was hit by a truck and several branches
had to be cut. There have been many speculations about the age of the baobab.
Usually, it is considered to be between 700 and 1500 years old.
The first photo of the “gros baobab” dates back to 1898, during the
French administration (Figure 1). According to official measurements, the
tree had then a circumference of 14.60 m at a height of 0.70 m above ground.
The GPS coordinates are 15º43.294' S, 046º18.300' E and the
altitude is 8 m. In 2013, the big baobab had a height of 15.6 m, the circumference
at breast height (cbh; at 1.30 m above mean ground level) was 21.21 m and the
overall wood volume of around 180 m3 (Figures 2 and 3). The circumference
at 0.70 m was 22.72 m. In 2018, the circumference cbh was only 2 cm larger,
reaching 21.23 m. The horizontal dimensions of the large canopy, which has
several large branches, are 26.6 (NS) x 31.5 (WE) m.
The impressive trunk exhibits a cluster structure, which consists of 6
fused ordinary/common stems, out of which two are very large, and a further
3 smaller binding stems.
At present, the Grand Baobab is in a general state of decline, with
several broken and damaged branches. It almost stopped growing during the
last decades. The pavement and the intense traffic around the tree probably
play an important role in this process.
Wood samples. Two wood samples were collected from the baobab
with an increment borer. One sample, labelled MJ-1, with the length of 0.30
m, was collected from the exterior of a large stem, at the height of 1.90 m. A
number of two tiny pieces/segments, each 10-3 m long (marked a and b),
were extracted from determined positions of sample MJ-1. Another sample,
labelled MJ-2, with the length of 0.34 m, was collected from a large primary
branch, at the height of 2.20 m. Two segments (marked a and b) were
extracted from this sample.
ADRIAN PATRUT, ROXANA T. PATRUT, LASZLO RAKOSY, ILEANA ANDREEA RATIU,
PASCAL DANTHU, JEAN-MICHEL LEONG POCK TSY, KARL F. VON REDEN
122
Figure 1. The first photograph of the baobab of Mahajanga taken in 1898.
Figure 2. General view of the Grand Baobab of Mahajanga.
RADIOCARBON DATING OF THE HISTORIC GRAND BAOBAB OF MAHAJANGA, MADAGASCAR
123
Figure 3. The image shows the large trunk of the Grand Baobab
surrounded by a fence.
AMS results and calibrated ages. Radiocarbon dates of the four sample
segments are listed in Table 1. The radiocarbon dates are expressed in 14C yr
BP (radiocarbon years before present, i.e., before the reference year 1950).
Radiocarbon dates and errors were rounded to the nearest year.
Calibrated (cal) ages, expressed in calendar years CE (CE, i.e., common
era), are also displayed in Table 1. The 1σ probability distribution (68.3%) was
selected to derive calibrated age ranges. For two segments (MJ-1b, MJ-2b),
the 1σ distribution is consistent with three ranges of calendar years, while for
one sample segment (MJ-2a) it corresponds to four ranges. In all these
ADRIAN PATRUT, ROXANA T. PATRUT, LASZLO RAKOSY, ILEANA ANDREEA RATIU,
PASCAL DANTHU, JEAN-MICHEL LEONG POCK TSY, KARL F. VON REDEN
124
cases, the confidence interval of one range is considerably greater than that
of the others; therefore, it was selected as the cal CE range of the segment
for the purpose of this discussion.
Table 1. AMS Radiocarbon dating results and calibrated ages of samples collected
from the Grand baobab of Mahajanga.
Sample
code
Depth1
[height2]
(m)
Radiocarbon
date [error]
(14C yr BP)
Cal CE range
[confidence
interval]
Assigned
year
[error]
(cal CE)
Sample
age
[error]
(cal CE)
MJ-1a
0.15
[1.90] - - - >Modern
MJ-1b
0.30
[1.90] 123 [± 16]
1712-1718 [4.3%]
1813-1835 [20.6%]
1885-1925 [43.3%]
1905
[± 20]
120
[± 20]
MJ-2a
0.20
[2.20] 158 [± 18]
1695-1711 [12.3%]
1719-1726 [5.0%]
1836-1883 [22.8%]
1925-... [18.1%]
1869
[± 24]
155
[± 25]
MJ-2b
0.34
[2.20] 214 [± 17]
1672-1680 [9.1%]
1733-1782 [52.8%]
1797-1803 [6.3%]
1757
[± 24]
265
25]
1 Depth in the wood from the sampling point.
2 Height above ground level.
For obtaining single calendar age values of sample segments, we
derived a mean calendar age of each sample segment, called assigned year,
from the selected range (marked in bold). Sample/segment ages represent
the difference between the year 2023 CE and the assigned year, with the
corresponding error. Sample ages and errors were rounded to the nearest
5 yr.
For one sample segment (MJ-1a), the age falls after the year 1950
CE, namely the 14C activity, expressed by the ratio 14C/12C, is greater than the
standard activity in the reference year 1950. Such values, which correspond
to negative radiocarbon dates, are termed greater than Modern (>Modern). In
such cases, the dated wood is young, being formed after 1950 CE.
This approach for selecting calibrated age ranges and single values
for sample ages was used in all our previous articles on AMS radiocarbon
dating of large and old angiosperm trees [6-20, 22-26].
RADIOCARBON DATING OF THE HISTORIC GRAND BAOBAB OF MAHAJANGA, MADAGASCAR
125
Dating results of sample segments. The sample MJ-1, with a length
of only 0.30 m, was collected from a large stem. The diameter in the sampling
direction is about 3.10 m, corresponding to radius of 1.55 m, which is also
the distance to the theoretical pith of this stem. As mentioned, the wood of
segment MJ-1a which originates from a depth of only 0.15 m, was formed after
the year 1950. The segment MJ-1b, from a depth of 0.30 m, had a radiocarbon
date of 123 ± 16 BP, which corresponds to a calibrated age of 120 ± 20
calendar yr. The sample MJ-1 was too short to provide significant information
about the true age of the baobab. We also collected two samples from another
stem, which were even shorter. This demonstrates that the stems have large
hollow parts, very probably due to the state of decline of the baobab.
The sample MJ-2, with a length of 0.34 m, was extracted from a
primary branch. The branch diameter in the sampling direction is 0.72 m. The
segment MJ-2a, from a depth of 0.15 m, had a radiocarbon date of 158 ± 18 BP,
which corresponds to a calibrated age of 155 ± 25 calendar yr. The segment
MJ-2b from a depth of 0.34 m, which is also the sample end, had a radiocarbon
date of 214 ± 17 BP corresponding to a calibrated age of 265 ± 25 calendar
yr.
Age of the Grand Baobab of Mahajanga. The age of the baobab
can be determined by extrapolating the age of the oldest dated segment, i.e.,
MJ-2b, to the calculated centre of the branch from which it originates. The
sample segment MJ-2b, with an age of 265 ± 25 yr, was extracted from a
distance of 0.34 m from the sampling point. The calculated centre of the
branch is located at 0.36 m from the sampling point. These values indicate
that the Big Baobab of Mahajanga is up to 300 yr old; more precisely, its age
is of 275 ± 25 years.
This age value is in good agreement with the circumference
measurements made over time, namely 14.60 m (at a height of 0.70 m) in
1898, 20.60 m (at 1.50 m) in 1979, 20.70 m (at 1.50 m) in 2011, 21.21 m (at
1.30 m) in 2013 and 21.23 m (at 1.30 m) in 2018. The mentioned values
show that the Grand Baobab grew very fast when it was young, due to the
sandy soil on limestone rock and also to the very high annual rainfall. The
values also show that the Grand Baobab almost stopped growing at least
over the last four decades and is probably close to the end of its life cycle.
We should mention that, at a distance of around 200 m, in a yard behind
the MCB bank, grows another very large African baobab (GPS coordinates
15º43.292' S, 046º18.672' E). It also has a cluster structure and is composed
of 10 fused stems (Figure 4). This baobab has a height of 18.1 m and a
circumference cbh of 20.05 m.
ADRIAN PATRUT, ROXANA T. PATRUT, LASZLO RAKOSY, ILEANA ANDREEA RATIU,
PASCAL DANTHU, JEAN-MICHEL LEONG POCK TSY, KARL F. VON REDEN
126
Figure 4. The photograph shows the second largest baobab of Mahajanga.
CONCLUSIONS
The research presents the AMS radiocarbon investigation results of
the historic Grand Baobab of Mahajanga, Madagascar. The baobab has a
cluster structure and consists of 6 fused ordinary stems and 3 smaller binding
stems. Two wood samples were collected from a large stem and from a
primary branch, which were dated by radiocarbon. The oldest dated sample
segment had a radiocarbon date of of 214 ± 17 BP, which corresponds to a
calibrated age of 265 ± 25 calendar years. The dating results indicate that
the Grand Baobab of Mahajanga is 275 ± 25 years old. It can be stated that
the historic baobab of Mahajanga started growing around the year 1750 CE.
The baobab of Mahajanga is in a state of decline and measures
should be taken to avoid further degradation of the tree.
RADIOCARBON DATING OF THE HISTORIC GRAND BAOBAB OF MAHAJANGA, MADAGASCAR
127
EXPERIMENTAL SECTION
Sample collection. The wood samples were collected with a Haglöf
CH 800 increment borer (0.80 m long, 0.0054 m inner diameter). A number
of four segments of the length of 10-3 m were extracted from predetermined
positions along the wood samples. The segments were processed and
investigated by AMS radiocarbon dating.
Sample preparation. The acid-base-acid pretreatment method was
used for removing soluble and mobile organic components [27]. The pretreated
samples were combusted to CO2 by using the closed tube combustion method
[28]. Next, CO2 was reduced to graphite on iron catalyst [29]. Eventually, the
resulting graphite samples were investigated by AMS.
AMS measurements. AMS radiocarbon measurements were performed
at the NOSAMS Facility of the Woods Hole Oceanographic Institution (Woods
Hole, MA, U.S.A.), by using the Pelletron ® Tandem 500 kV AMS system.
The obtained fraction modern values, corrected for isotope fractionation with
the normalized δ13C value of -25 0/00, were converted to a radiocarbon date.
Calibration. Radiocarbon dates were calibrated and converted into
calendar ages with the OxCal v4.4 for Windows [30], by using the SHCal20
atmospheric data set [31].
ACKNOWLEDGEMENTS
The investigation of the baobab was authorised by the Forestry Direction of
the Ministry of Environment, Ecology and Forestry of Madagascar and by the
Madagascar National Parks. The research was funded by the Romanian Ministry of
Research CNCS-UEFISCDI under grant PN-III-P4-ID-PCE-2020-2567, No. 145/2021.
REFERENCES
1. G.E. Wickens, Kew Bull., 1982, 37(2), 172-209.
2. D.A. Baum, Ann. Mo. Bot. Gard., 1995, 82, 440-471.
3. G.E. Wickens, P. Lowe, "The Baobabs: Pachycauls of Africa, Madagascar and
Australia", Springer, Dordrecht, 2008, pp. 232-234, 256-257, 295-296.
ADRIAN PATRUT, ROXANA T. PATRUT, LASZLO RAKOSY, ILEANA ANDREEA RATIU,
PASCAL DANTHU, JEAN-MICHEL LEONG POCK TSY, KARL F. VON REDEN
128
4. A. Petignat, L. Jasper, “Baobabs of the world: The upside down trees of Madagascar,
Africa and Australia”, Struik Nature, Cape Town, 2015, pp. 16-86.
5. G.V. Cron, N. Karimi, K.L. Glennon, C.A. Udeh, E.T.F. Witkowski, S.M. Venter,
A.E. Assobadjo, D.H. Mayne, D.A. Baum, Taxon, 2016, 65, 1037-1049.
6. A. Patrut, K.F. von Reden, D.A. Lowy, A.H. Alberts, J.W. Pohlman, R. Wittmann,
D. Gerlach, L. Xu, C.S. Mitchell, Tree Physiol., 2007, 27, 1569-1574.
7. A. Patrut, K.F. von Reden, R. Van Pelt, D.H. Mayne, D.A. Lowy, D. Margineanu,
Ann. Forest Sci., 2011, 68, 93-103.
8. A. Patrut, K.F. von Reden, D.H. Mayne, D.A. Lowy, R.T. Patrut, Nucl. Instrum.
Methods Phys. Res. Sect. B, 2013, 294, 622-626.
9. A. Patrut, S. Woodborne, K.F. von Reden, G. Hall, M. Hofmeyr, D.A. Lowy,
R.T. Patrut, PLOS One, 2015, 10(1): e0117193.
10. A. Patrut, S. Woodborne, K.F. von Reden, G. Hall, R.T. Patrut, L. Rakosy,
J-M. Leong Pock Tsy, D.A. Lowy, D. Margineanu, Radiocarbon, 2017, 59(2),
435-448.
11. A. Patrut, S. Woodborne, R.T. Patrut, L. Rakosy, D.A. Lowy, G. Hall, K.F. von
Reden, Nature Plants, 2018, 4(7), 423-426.
12. A. Patrut, R.T. Patrut, L. Rakosy, D.A. Lowy, D. Margineanu, K.F. von Reden,
Studia UBB Chemia, 2019, LXIV, 2 (II), 411-419.
13. A. Patrut, S. Woodborne, R.T. Patrut, G. Hall, L. Rakosy, C. Winterbach,
K.F. von Reden, Forests, 2019, 10, 983-993.
14. A. Patrut, A. Garg, S. Woodborne, R.T. Patrut, L. Rakosy, I.A. Ratiu, PLOS One,
2020, 15(1): e0227352.
15. A. Patrut, R.T. Patrut, P. Danthu, J-M. Leong Pock Tsy, L. Rakosy, D.A. Lowy,
K.F. von Reden, PLOS One, 2016, 11(1): e146977.
16. A. Patrut, K.F. von Reden, P. Danthu, J-M. Leong Pock Tsy, R.T. Patrut, D.A.
Lowy, PLOS One, 2015, 10(3): e0121170.
17. A. Patrut, K.F. von Reden, P. Danthu, J-M. Leong Pock Tsy, L. Rakosy, R.T.
Patrut, D.A. Lowy, D. Margineanu, Nucl. Instr. Methods Phys. Res. Sect. B,
2015, 361, 591-598.
18. R.T. Patrut, A. Patrut, J-M. Leong Pock Tsy, S. Woodborne, L. Rakosy,
P. Danthu, I.A. Ratiu, J. Bodis, K.F. von Reden, Studia UBB Chemia, 2019, LXIV,
4, 131-139.
19. A. Patrut, R.T. Patrut, J-M Leong Pock-Tsy, S. Woodborne, L. Rakosy, I-A. Ratiu,
J. Bodis, P. Danthu, Studia UBB Chemia, 2020, LXV, 4, 151-158.
20. A. Patrut, R.T. Patrut, J-M Leong Pock Tsy, P. Danthu, S. Woodborne,
L. Rakosy, I.A. Ratiu, Forests, 2021, 12, 1258.
21. C. Cornu, P. Danthu, “Baobabs de Madagascar: Guide d’identification illustré”,
CIRAD, Montpellier, 2015, pp.16-17.
22. A. Patrut, R.T. Patrut, L. Rakosy, K.F. von Reden, DRC Sustainable Future,
2020,1(1), 33-47.
23. A. Patrut, R.T. Patrut, L. Rakosy, D. Rakosy, I.A. Ratiu, K.F. von Reden, Studia
UBB Chemia, 2021, LXVI, 1, 153163.
24. A. Patrut, R.T. Patrut, L. Rakosy, I.A. Ratiu, D.A. Lowy, K.F. von Reden,
Dendrochronologia, 2021, 70, 125898.
RADIOCARBON DATING OF THE HISTORIC GRAND BAOBAB OF MAHAJANGA, MADAGASCAR
129
25. A. Patrut, R.T. Patrut, L. Rakosy, I.A. Ratiu, J. Bodis, M.N. Nassor, K.F. von
Reden, Studia UBB Chemia, 2022, LXVII, 2, 143153.
26. A. Patrut, R.T. Patrut, L. Rakosy, D. Rakosy, W.Oliver, I.A. Ratiu, D.A. Lowy, G.
Shimbii, S. Woodborne, K.F. von Reden, Forests, 2022, 13, 1889.
27. N.J. Loader, I. Robertson, A.C. Barker, V.R. Switsur, J.S. Waterhouse, Chem.
Geol.,1997, 136(3), 313–317.
28. Z. Sofer, Anal. Chem., 1980, 52(8), 1389-1391.
29. J.S. Vogel, J.R. Southon, D.E. Nelson, T.A. Brown, Nucl. Instrum. Methods Phys.
Res. Sect. B, 1984, 5, 289-293.
30. C. Bronk Ramsey, Radiocarbon, 2009, 51, 337-360.
31. A.G. Hogg, T.J. Heaton, Q. Hua, J.G. Palmer, C.S.M. Turney, J. Southon,
A. Bayliss, P.G. Blackwell, G. Boswijk, C.B. Ramsey, C. Pearson, F. Petchey,
P.J. Reimer, R.W. Reimer, L. Wacher, Radiocarbon, 2020, 62(4), 759-778.
ResearchGate has not been able to resolve any citations for this publication.
Article
Full-text available
If radiocarbon measurements are to be used at all for chronological purposes, we have to use statistical meth-ods for calibration. The most widely used method of calibration can be seen as a simple application of Bayesian statistics, which uses both the information from the new measurement and information from the 14 C calibration curve. In most dating applications, however, we have larger numbers of 14 C measurements and we wish to relate those to events in the past. Baye-sian statistics provides a coherent framework in which such analysis can be performed and is becoming a core element in many 14 C dating projects. This article gives an overview of the main model components used in chronological analysis, their mathematical formulation, and examples of how such analyses can be performed using the latest version of the OxCal soft-ware (v4). Many such models can be put together, in a modular fashion, from simple elements, with defined constraints and groupings. In other cases, the commonly used "uniform phase" models might not be appropriate, and ramped, exponential, or normal distributions of events might be more useful. When considering analyses of these kinds, it is useful to be able run sim-ulations on synthetic data. Methods for performing such tests are discussed here along with other methods of diagnosing pos-sible problems with statistical models of this kind.
Article
Full-text available
We present details of a modified technique for the extraction of α-cellulose from wood samples. The revised technique, based upon the sodium chlorite oxidation method of Green (1963) utilises an ultrasonic bath and small Soxhlet thimbles to prepare α-cellulose from silvers of wholewood. These modifications facilitate the rapid batch processing of small wholewood samples to α-cellulose and yield a material with sufficient homogeneity as required for palaeoclimatic reconstruction.
Book
First and only fully comprehensive account of all eight species of Adansonia Contains much new information Highly interesting for scientists, academics and laypeople This is the only comprehensive account of all eight species in the genus Adansonia. It describes the historical background from the late Roman period to the present. It covers the extraordinary variety of economic uses of baobabs, famous trees, folk traditions and mythology, art associations, life cycle, natural history, cultivation, conservation, distribution and ecology, and phytogeography. There are also appendices on vernacular names, gazetteer, economics, nutrition and forest mensuration. This book fills a gap in the botanical literature. It deals with a genus that has fascinated and intrigued scientists and lay persons for centuries. It will appeal to scientists and academics as well as tropical horticulturalists, conservationists and general interest readers. It includes all the available scientific information about each of the eight species, and contains a good deal of original research on the history, ethnobotany and biology of the genus. There is even a chapter devoted to areas where further research is required. © 2008 Springer Science + Business Media, B.V. All rights reserved.
  • G E Wickens
G.E. Wickens, Kew Bull., 1982, 37(2), 172-209.
Baobabs of the world: The upside down trees of Madagascar, Africa and Australia
  • A Petignat
  • L Jasper
A. Petignat, L. Jasper, "Baobabs of the world: The upside down trees of Madagascar, Africa and Australia", Struik Nature, Cape Town, 2015, pp. 16-86.
  • G V Cron
  • N Karimi
  • K L Glennon
  • C A Udeh
  • E T F Witkowski
  • S M Venter
  • A E Assobadjo
  • D H Mayne
  • D A Baum
G.V. Cron, N. Karimi, K.L. Glennon, C.A. Udeh, E.T.F. Witkowski, S.M. Venter, A.E. Assobadjo, D.H. Mayne, D.A. Baum, Taxon, 2016, 65, 1037-1049.
  • A Patrut
  • K F Von Reden
  • D A Lowy
  • A H Alberts
  • J W Pohlman
  • R Wittmann
  • D Gerlach
  • L Xu
  • C S Mitchell
A. Patrut, K.F. von Reden, D.A. Lowy, A.H. Alberts, J.W. Pohlman, R. Wittmann, D. Gerlach, L. Xu, C.S. Mitchell, Tree Physiol., 2007, 27, 1569-1574.
  • A Patrut
  • K F Von Reden
  • R Van Pelt
  • D H Mayne
  • D A Lowy
  • D Margineanu
A. Patrut, K.F. von Reden, R. Van Pelt, D.H. Mayne, D.A. Lowy, D. Margineanu, Ann. Forest Sci., 2011, 68, 93-103.
  • A Patrut
  • K F Von Reden
  • D H Mayne
  • D A Lowy
  • R T Patrut
A. Patrut, K.F. von Reden, D.H. Mayne, D.A. Lowy, R.T. Patrut, Nucl. Instrum. Methods Phys. Res. Sect. B, 2013, 294, 622-626.
  • A Patrut
  • S Woodborne
  • K F Von Reden
  • G Hall
  • M Hofmeyr
  • D A Lowy
  • R T Patrut
A. Patrut, S. Woodborne, K.F. von Reden, G. Hall, M. Hofmeyr, D.A. Lowy, R.T. Patrut, PLOS One, 2015, 10(1): e0117193.