SEASONAL DIMORPHISM OF CHAMAEPHYTES 



213 



body o{ Anabasis is markedly reduced by the shedding of the brachyblasts 

 and the upper portion of the doHchoblasts. 



(i) Hahxylon articulatum. This plant has a Hfe cycle very similar to that of 

 Anabasis. 



EXTENT OF SEASONAL BODY REDUCTION 



Measurements of the extent of seasonal body reduction were carried out 

 in desert and Mediterranean plants through two successive years, 1957 and 



X XI XII I II III IV V VI VII VIII IX 

 1957 1958 



Fig. 4. Annual march of dry weight (grams) of the transpiring body of desert plants. 

 h.m..-Arteniisia monosperina H.a..- Hahxylon articulatum 



A.ha. -Artemisia herba alba N.m.-Noea mucronata 



A.a. -Anabasis articulata Z,A.- Zygophyllum dumosum 



• 



1958, differing in their annual rainfall. The values for Re vi vim were 177-5 



mm for the winter of 1956-57 and only 32-4 mm for the winter of 1957-58. 



The corresponding values for Jerusalem were 621 mm and 384 mm 



respectively. 



