(e) Low and medium transpiring biseasonal and surface reducing articulate deep- 

 rooters with transpiration decreasing in summer (e.g. Anabasis articulata, 

 Haloxylon articulatum). 



(f) Low and medium transpiring, biseasonal, surface reducing, non- succulent flat- 

 rooters with transpiration decreasing in summer (e.g. Artemisia Herba alba). 



(g) Low and medium transpiring, biseasonal, surface reducing, glyco- and halo- 

 succulent flat-rooters with transpiration decreasing in summer (e.g. Zygopbyl- 

 lum dumosum, Reaumuria palaestina). 



Summary 



(1) The Near East deserts constitute a more or less uniform entity in its clima- 

 tical and vegetational aspect but is heterogeneous from the point of view of plant 

 hydro - ecology. 



(2) As moisture is the minimum factor, all features associated with hydro - 

 ecology are of supreme importance to plant life. 



(3) There is a variety of morphological, phenological and physiological types 

 among the local vegetation, all reducing the amount of water expenditure lost 

 through transpiration. 



(4) Of the various life forms the chamaephyte biseasonal are the most impor- 

 tant elements in th^ evergreen vegetation cover of the desert. 



(5) The life form analysis in its conventional approach is of little significance 

 to hydro- ecology. But in the light of seasonal surface reduction of the transpiring 

 body it is hydro- ecologically very important. 



(6) A variety of morpho - ecological types has been distinguished among the 

 permanent vegetation of the desert. In most of them seasonal surface reduction is 

 considerable. 



(7) Both with regard to transpiration intensity and to osmotic pressure of cell 

 sap, various types have been distinguished in the vegetation of the desert. 



(8) An attempt has been made to establish combined hydro- economical types 

 based on properties, associated with the water- economy of the plants. 



References 



Birand, H. A. 1938. Untersuchungen zur Wasseroekologie der Steppenpflanzen bei Ankara. 

 ]ahrb. wiss. Bot. 87: 93- 172. 



Eig, A. 1938. On the phytogeographical subdivision of Palestine. Palest. J. Bot. J. Ser. 1: 

 4-12. 



Eig, A. 1946. Synopsis of the phytosociological units of Palestine. Palest. J. Bot. J. Ser. 3: 

 183-246. 



Evenari (Schwarz) M. & Richter, R. 1937. Physiological - ecological investigations in the 

 wilderness of Judaea. J. Linn. Soc. Bot. 51: 333-381. 



Harris, J. A. 1934. The physico- chemical properties of plant saps in relation to phyto- 

 geography. Minneapolis: Univ. Minnesota Press. 



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