Khor Rori natural environment (Dhofar, Oman).

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Since 2000, the Tropical Herbarium Studies Centre
(Centro Studi Erbario Tropicale) and the Department
of Plant Biology (Dipartimento di Biologia Vegetale)
of the University of Florence have been engaged in re
-
search activity in Dhofar (Oman). They have worked
in close collaboration with the archaeological mission
from the University of Pisa, led by Prof. A. Avanzini,
responsible for the excavations of the ancient city of
Sumhuram.
Between 2000 to 2004, six expeditions have been un
-
dertaken whose main aim was to study the flora and
vegetation of the region, as well as two scientific mis
-
sions dedicated to reconstructing the plant palaeo-en
-
vironment of the Sumhuram site (3
rd
century BC – 5
th
century AD) through the analyses of fossil pollen ex
-
tracted from different excavation levels. In the years
2002 and 2004, MIUR awarded inter-university fund
-
ing (Pisa, Florence and Venice) for research activity
in Dhofar.
Research was carried out with the full backing of the
Oman Offices for Cultural Affairs and some of the
field-activities were agreed together with the Oman
Authorities; this is the case of establishing the bound
-
aries of the wadi Doka Natural Park (UNESCO site
approx. 42 km north of Salalah), a typical pre-desert
habitat where an ancient and thriving population of
Boswellia sacra, the incense tree, still survives today
(fig. 1).
The subject of incense and all its implications has been
the main driving force behind our research. In particu
-
lar we were concerned with the present distribution
of the plant in the territory, the number of individuals
in each population and their phyto-sanitary condition,
as well as the residual commercial activity linked to
harvesting the resin.
Some of the most important areas of Dhofar were
examined, where still today considerable concentra
-
tions of Boswellia sacra grow (al Mughsayl,
wadi
Adonib, wadi Doka, Sadh, Hasik). Each site was sur-
veyed to document its environmental characteristics
and floristic components. However, the entire region
was studied comprehensively, allowing us to report
several new localities where incense trees still grow
today, albeit isolated or in small groups; this testifies
that distribution was more widespread in the past than
in modern times. The increased climatic aridity, ex
-
cessive exploitation by man (grazing by dromedaries
and goats, felling for fire wood) are the main causes
behind the marked decline in
Boswellia populations,
both in the number of individuals per locality and their
occurrence over the whole territory.
Research into incense forges a strong link between
past and present, since Dhofar has been one of the an
-
cient countries from where caravans and ships loa
ded
with the precious resin left for the Mediterranean and
India. The port of the ancient city of Sumhuram also
SCIENTIFIC ACTIVITY IN DHOFAR (2000 – 2004)
Botanical mission of Florence University
Mauro Raffaelli, Marcello Tardelli, Stefano Mosti

MAURO RAFFAELLI, MARCELLO TARDELLI, STEFANO MOSTI
seems to have been involved in the incense trade
1
as it
was from here that the maritime routes reached Egypt
and as far as Rome via the Arabian and Red Seas.
Our research not only concerned the issue of incense,
it also looked at the flora of Dhofar. For this reason we
collected specimens from all the localities we visited
that have helped increase the collection of the
Tropical
Herbarium of Florence. Their study, already in part un-
derway, will provide important taxonomical revisions.
Some results have already been published and others
are in preparation. A new species, Desmidorchis tar
-
dellii Mosti et Raffaelli, belonging to Asclepiadaceae
family, has been recently described
2
.
Working within and alongside the Italian Archaeologi
-
cal Mission (IMTO) of the University of Pisa in the
role of botanists, we have also been involved in the
study of the natural environment surrounding the an
-
cient city of Sumhuram (Khor Rori). According to the
IMTO (Italian Mission to Oman) and the Office for
Cultural Affairs of Oman, this site is to be an archaeo
-
logical park. Nevertheless, the intention is to render
both the human environment of the past, represented
by the excavations of the ancient citadel, and the natu
-
ral environment of today available to the public, per
-
haps by creating guided walks to illustrate the natural
features from this point of view.
Concerning the palynological analyses, they were car
-
ried out with the aim to improve our knowledge about
the palaeo-environment surrounding the ancient city
of Sumhuram. A long statigraphical sequence, which
covers most part of the life of Sumhuram, was sam
-
pled immediatly outside the city wall; short sections
and stratigraphic units were sampled inside the town.
The identification of the ancient pollen morphotypes
was particularly difficult, since the pollen morphology
of the plants which grow in the area is poorly known.
Therefore, it was necessary to collect and study the
pollen morphology of the most common plants wide
-
spread in the coastal plain and the escarpment of Dho
-
far. The construction of a palynotheca started simul
-
taneously with archaeopalinological investigations in
the site of Sumhuram. The study of the pollen mor
-
phology at scanning electron microscope is currently
in progress.
REFERENCES
A
VANZINI A.
2002 -
«The history of the Khor Rori area. New
perspectives», in A. Avanzini (ed.), Khor Rori Report
1, Arabia Antica 1, Pisa, pp. 13-27.
M
OSTI S., RAFFAELLI M.
2004 - «Desmidorchis tardellii (Asclepiadaceae) a
new species from Dhofar (southern Oman)
», in Web-
bia 59(2), pp. 285-291.
Figure 1– left: Dhofar, a view of the “wadi Doka frankincense Park”;
right: an old tree of Boswellia sacra at wadi Doka.
1
AVANZINI 2002.
2
MOSTI, RAFFAELLI 2004.

Khor Rori is one of the many creeks (khor) along the
coast of the Arabian Sea; this khor was excavated by
the erosive action of the wadi Darbat during rainy
phases in the climate, the last of which in the Arabian
Peninsula dates back to at least 4.000- 8.000 BC. The
old colonisers, who arrived around the 3
rd
century BC,
must have realised that this particular khor, on account
of its morphology, was an ideal natural port. Indeed,
as can still been seen today, its outlet to the ocean is
flanked by two long, rocky “mesas” (flat hills) parallel
to the coast, one on the right and the other to the left,
that offer protection from storms and the ocean waves.
Thus it was an excellent site for a settlement and com
-
merce, especially maritime, and so around 3
rd
century
BC construction began on a port and a fortified citadel,
Sumhuram, set on a small area of raised ground just
above the final section of wadi Darbat.
Today the archaeological excavations at Sumhuram lie
in an area heavily exploited by man, in a plain rendered
sterile by over-grazing by dromedaries and goats that
has been going on for centuries. Especially behind
the citadel, as far as the Jebel Qara hills, stretches an
almost bare rocky-gravel plain with sparse bushes of
Acacia tortilis
, Commiphora habessinica and Cassia
holosericea and a few herbaceous plants here and there
(Calotropis procera, Cometes abyssinica, Vernonia
arabica) and some grasses (Cenchrus pennisetiformis,
Dactyloctenium aristatum, Dichanthium foveolatum,
etc); a slightly thicker vegetation consisting of low
Acacia tortilis
, Commiphora habessinica, Ziziphus
leucodermis and Cissus quadrangularis bushes
develops along the short, shallow wadis, that cut their
way through the bare, rocky plain on their way to the
ocean.
Below the citadel, to the left, stretch wet saline depres
-
sions on the edges of which grow hygrophilous plants
such as Cyperus conglomeratus
, Schoenoplectus lito-
ralis, Juncus rigidus and on the ground near the water,
large lawns of Bacopa monnieri.
On the right of the citadel, along the final stretch of
the wadi Darbat, reed thickets of Phragmites australis
and Juncus rigidus grow (fig. 2), while, dense agglom-
erates of semi-submerged Myriophyllum thrive in the
water of the wadis.
The two “mesas” that flank the entrance to the port,
again used for grazing but to a lesser extent, are es
-
pecially covered with herbaceous vegetation and sup
-
port a more diversified flora on account of the higher
number of habitats that develop on these low hills (dif-
ferent exposition of the slopes, different influx of the
monsoon wind between the north and south slopes,
different soil types: rocky and sandy, cliffs and
shady
hollows, etc.). The sparse bushes include Salvadora
persica and Cadaba farinosa, whilst the herbaceous
plants abound with Heliotropium fartakense
, Cleome
brachycarpa, Suaeda fruticosa, Fagonia luntii, Com-
KHOR RORI NATURAL ENVIRONMENT
Mauro Raffaelli, Marcello Tardelli, Stefano Mosti

MAURO RAFFAELLI, MARCELLO TARDELLI, STEFANO MOSTI
MAURO RAFFAELLI, MARCELLO TARDELLI, STEFANO MOSTI
Figure 2 – top: Khor Rori, the final stretch of wadi Darbat and the two ‘mesas’ flanking its outlet to the Indian ocean;
bottom: wadi Darbat valley, thickets of Ziziphus spina-christi near the water and luxuriant woods of Anogeissus
dhofarica on the hills.

micarpus boissieri, Limonium axillare, Lindembergia
muraria together with some grasses.
Behind the citadel, beyond the coastal plain, after
about 4-5 km, begin to rise the slopes of Jebel Qara,
covered with a thick woodland of
Jatropha dhofarica,
Blepharispermum hirtum
, Delonix elata, Anogeissus
dhofarica, Commiphora habessinica, C. gileaden-
sis and some plants of Boscia arabica; there are also
the creeper Cissus quadrangularis and the succulents
Adenium obesum
and Sansevieria ehrenbergii, on the
rocky slopes exposed to the sun.
A short distance from the Khor Rori foot hill belt opens
the wadi Darbat valley (fig. 2), where the presence of
water (permanent in this stretch of the wadi) allows
the formation of Ziziphus spina-christi woodlets and
various species of
Ficus (F. sycomorus and F. salicifo-
lia) that can reach quite large dimensions; the slopes
of the wadi Darbat valley enjoy the beneficial influx of
the south-west monsoon. During the rainy season they
are covered with luxuriant Anogeissus woods.
Finally, not far from Sumhuram (approx. 10 km), in the
direction of Mirbat, lies wadi Hinna where a Baobab
(Adansonia digitata) wood grows (fig. 3). This is a
very “important finding” as it is one of the two sites
in Dhofar (the other is Dalkut near the Yemen border)
where this African plant can be found; its occurrence
is probably due to its introduction in the ancient past.
Considering their naturalistic importance, the luxu
-
riant wadi Darbat valley and the wadi Hinna with
its baobab wood could be mentioned as interesting
places to visit in the future Khor Rori Archaeologi
-
cal-Natural Park.
SCIENTIFIC ACTIVITY IN DHOFAR (2000 – 2004): KHOR RORI NATURAL ENVIRONMENT

MAURO RAFFAELLI, MARCELLO TARDELLI, STEFANO MOSTI
MAURO RAFFAELLI, MARCELLO TARDELLI, STEFANO MOSTI
Figure 3 – top: Adansonia digitata (baobab), at wadi Hinna, between Khor Rori and Mirbat.
bottom, left: Adenium obesum; bottom, right: Desmidorchis flavus.

Plants and natural environments of Khor Rori
Collected plants and related environments A B C D E
A) Coastal plain
B) Wet areas
C) “Mese” (low and flat hills)
D) Outlet of wadi Darbat
E) Foothills of Jebel Qara
Acanthaceae
Barleria proxima
Lindau
+ +
Blepharis scindica T. Anderson
+
Neuracanthus robecchii
(Lindau) C.B. Clarke
+
Agavaceae
Sansevieria ehrenbergii
Schweinf.
+
Aizoaceae
Aizoon canariense L.
+ +
Amaranthaceae
Aerva javanica (Burm. f.) Juss. in Schultes
+ + +
Digera muricata (L.) Mart. ssp. muricata
+ + +
Pupalia lappacea (L.) Juss. var. velutina (Moq.) Hook. f.
+ +
Apocinaceae
Adenium obesum (Forssk.) Roem. & Schult.
+
Aristolochiaceae
Aristolochia bracteata Retz
+ +
Asclepiadaceae
Calotropis procera (Aiton) W.T. Aiton
+
Desmidorchis flavus (N.E. Br.) Meve & Liede
+
Desmidorchis tardellii Mosti & Raffaelli
+
Glossonema varians (Stocks) J. D. Hook
+
Boraginaceae
Arnebia hispidissima (Lehm.) DC.
+
Heliotropium fartakense
O. Schwartz
+ +
Heliotropium longiflorum
(H. & S.) ex A.D.C.) Jaub. & Spach.
+ +
Trichodesma hildebrandtii
Guerke
+
Burseraceae
Commiphora habessinica (Berg.) Engl.
+ + +
Commiphora gileadensis (L.) Christ
+
Capparaceae
Boscia arabica Pestalozzi
+
Cadaba farinosa Forssk.
+ + +
Cleome austroarabica
Chamberlain & Lamond
+ +
Cleome brachycarpa (Forssk.) Vahl ex DC.
+ +
SCIENTIFIC ACTIVITY IN DHOFAR (2000 – 2004): KHOR RORI NATURAL ENVIRONMENT

MAURO RAFFAELLI, MARCELLO TARDELLI, STEFANO MOSTI
MAURO RAFFAELLI, MARCELLO TARDELLI, STEFANO MOSTI
Collected plants and related environments A B C D E
Caryophyllaceae
Cometes abyssinica R. Br.
+
Polycarpaea spicata Wight ex Arn.
+
Chenopodiaceae
Suaeda fruticosa Forssk. ex Gmelin
+ +
Combretaceae
Anogeissus dhofarica A.J. Scott
+
Commelinaceae
Commelina forskhalei Vahl
+
Compositae
Blepharispermum hirtum Oliv.
+
Pluchea arabica (Boiss.) Kaiser & Lack
+
Vernonia arabica F.G. Davies
+ + +
Convolvulaceae
Cressa cretica
L.
+ +
Convolvulus glomeratus Choisy
+ +
Cucurbitaceae
Luffa acutangula (L.) Roxb.
+
Cyperaceae
Cyperus conglomeratus Rottb.
+ +
Schoenoplectus litoralis (Schrad.) Palla
+ +
Euphorbiaceae
Andrachne aspera Spreng var. glandulosa A. Rich.
+
Euphorbia hirta L.
+
Euphorbia smithii S. Carter
+
Jatropha dhofarica
A. R.- Sm.
+
Gramineae
Cenchrus pennisetiformis Hochst. & Steud.
+ + +
Cenchrus setigerus Vahl
+
Dactyloctenium aristatum Link.
+ +
Dichanthium foveolatum (Del.) Roberty
+ +
Leptothrium senegalense (Kunth) W.D. Clayton
+ +
Phragmites australis (Cav.) Trin. ex Steud.
+
Urochondra setulosa (Trin.) C.E. Hubb.
+ +
Holoragaceae
Myriphyllum sp.
+ +
Juncaceae
Juncus rigidus Desf.
+ +
Labiatae
Ocimum forskohlei Benth.
+
Orthosiphon pallidus Royle.
+

Collected plants and related environments A B C D E
Leguminosae
Acacia tortilis (Forssk.) Hayne
+ + +
Cassia holosericea Fresen.
+ + +
Delonix elata (L.) Gamble
+
Indigofera volkensii Taub.
+
Prosopis cineraria
(L.) Druce
+ +
Rhynchosia pulverulenta Stocks
+
Liliaceae
Dipcadi sp.
+
Malvaceae
Gossypium stoksii Masters in Hook f.
+ +
Senra incana (Cav.) DC.
+ +
Nyctaginaceae
Boerhavia diffusa
L.
+ +
Commicarpus boissieri (Heimerl) Cufod.
+ +
Commicarpus stenocarpus (Chiov.) Cufod.
+ +
Plumbaginaceae
Dyerophytum indicum (Gibs ex Wight) O. Kuntze
+
Limonium axillare
(Forssk.) O. Kuntze
+ + +
Plumbago zeylanica L.
+
Polygalaceae
Polygala erioptera DC. ssp. erioptera
+
Portulacaceae
Portulaca cfr. dhofarica Gilbert / quadrifida L.
+
Talinum portulacifolium (Forssk.) Aschers. & Schweinf.
+ +
Resedaceae
Ochradenus baccatus Del.
+
Rhamnaceae
Ziziphus spina-christi (L.) Willd.
+
Ziziphus leucodermis (Bak.) O. Schwartz
+
Rutaceae
Haplophyllum tuberculatum
(Forsskl.) A. Juss.
+
Salvadoraceae
Salvadora persica (L.) Garcin
+ + +
Scrophulariaceae
Bocopa monnieri (L.) Pennell
+ +
Lindembergia muraria
(Roxb.) Bruhl
+ +
Sterculiaceae
Hermannia paniculata Franch.
+
Melhania muricata Balf. f.
+
Sterculia africana
(Forssk.) Fiori
+
Tiliaceae
Corchorus trilocularis
L.
+
SCIENTIFIC ACTIVITY IN DHOFAR (2000 – 2004): KHOR RORI NATURAL ENVIRONMENT

MAURO RAFFAELLI, MARCELLO TARDELLI, STEFANO MOSTI
Collected plants and related environments A B C D E
Vitaceae
Cissus quadrangularis L.
+ + + +
Zygophyllaceae
Fagonia luntii Baker
+ +
Fagonia shweinfurthii Hadidi
+
Zygophyllum simplex L. f.
+ + +