Chorology

Arabian regional subzone, Nubo-Sindian local centre of endemism, Somali-Masai regional centre of endemism, Afromontane archipelago-like regional centre of endemism.

1. •The science which treats of the laws of distribution of living
organisms over the earth's surface as to latitude, altitude,
locality, etc.
•The science of describing localities; chorography.
•The science of the geographical distribution of plants and
animals; zoögeography and phytogeography.

2. The rain fed
highlands of the
western and
southwestern
regions (Sarawat
Mountains)
The vast arid and
extra arid lands of
the interior (Najd)

5. Draw a map to illustrate the
phytogeographical regions of KSA
Five min.

6. 1. Arabian Regional sub zone. 2. Nubo-Sindian local centre of endemism. 3. Somali-
Masai regional centre of endemism. 4.Afromontane Archipelago-like regional centre
of endemism.

7. The Arabian Regional subzone is the largest
phytogeographical reigon in Saudi Arabia,
covering central, northern and eastern regions.
This area is generally arid with an average
annual rainfall of 120 mm and an average
maximum temperature of 48
0
C. during July-
September and an average minimum
temperature of 8
0
C. during December-
February.

8. 1. Anabsis articulate, 2. Astragalus spinosus, 3. Calligonum comosum, 4.
Gymnocarpos decandrum, 5. Haloxylon salicornicum, 6. Helianthemum lippii,
7. Morettia canescens, 8. Neurada procumbens, 9. Paronychia Arabica, 10.
Polycarpaea repens, 11. Retama raetam, 12. Salsola tetrandra.
1 2 3 4
5 6 7 8
9 10 11 12

9. This is a narrow strip of land bordering the
coastal regions of the Arabian Peninsula, often
difficult to differentiate from the neighbouring
phytogeographical divisions. Phytogeographers
are of the view that the area covered by the
Nubo-Sindian zone, particularly in the southern
regions of the Arabian Peninsula should be
extended further towards the interior parts of
the Peninsula.

10. 1. Aerva javanica, 2. Acacia raddiana, 3. Acacia tortilis, 4. Calotropis
procera, 5. Capparis sinaica, 6. Cocculus pendulus, 7.Halopeplis perfoliata, 8.
Indigofera spinosa, 9. Panicum turgidum, 10. Salvadora persica, 11. Salvia
aegyptiaca
1 2 3 4
5 6 7 8 9
10 11

11. This region covers the low altitude areas of
southwestern region. These areas are
influenced by the subtropical climate and
dominated by vegetation similar to that of north
east Africa.

12. 1. Acacia hamulosa, 2. Acacia mellifera, 3. Breonadia salicina, 4. Cadaba
longifolia, 5. Carissa edulis, 6. Celtis Africana, 7. Commiphora spp., 8.
Dodonaea angustifolia, 9. Euclea schimperi, 10. Ficus cordata ssp. Salicifolia,
11. Ficus palmata, 12. Forsskaolea viridis,
1 2 3 4
5 6 7 8
9
10 11 12

13. 13. Maytenus parviflorus, 14. Ochna inermis, 15. Premna resinosa, 16. Psiadia
puntulata, 17. Pterolobium stellatum, 18. Sarcostemma viminale, 19. Trichilia
emetica
13 14 1615
17 1918

14. The areas belonging to this phytochorion is
the most important part of Saudi Arabia
and the Arabian Peninsula in general in
terms of vegetation and speciation. These
areas are situated between 1000 to 3000 m
above sea level and are similar to the high
altitude mountains of north-eastern and eastern
parts of Africa, both floristically and
ecologically.

15. 1. Acacia origena, 2. Buddleja polystachya, 3. Cadia purpurea, 4. Campanula
edulis, 5. Dombeya torrida, 6. Erica arborea, 7. Hypericum revolutum, 8. Juniperus
procera
1 2 3 4
5 6 7 8

16. 9. Lavandula dentate, 10. Maesa lanceolata, 11. Myrsine Africana, 12. Rhamnus
staddo, 13. Rumex nervosus, 14. Salvia merjamie, 15. Senecio hadiensis, 16.
Solanum schimperianum, 17. Teclea nobilis
9
10 11 12 13
14 1615 17