CHARACTEKS OF THE LEAVES OF THE DATE PALM. 



23 



V 



tlirough the middle of 



to 11 



inches up to 



U or 2 



inches wide with narrow at- 

 tenuate tips, gradually dimin- 

 ishing to about 10 or 12 inches 

 long at the apex. The pulyini 

 are hut moderately developed 

 and creamy in color. 



The lower 10 or 15 pinnae on 

 either side have a sohd neck, 

 which will be called the coUum, 

 from one-half inch to 2 inches 

 in length, just above the pul- 



vinus, from which the pinnse 

 expand into the folded blade of 

 normal form. These are most 

 strongly developed on the re- 

 trorse class of pinnse. This 

 character, while slightly devel- 

 oped in a few other Egyptian 

 varieties, is almost an identi- 

 fying character for this variet}^. 

 The pinnae blades are smooth 

 and rather soft, not rigidly acute 

 at the apex, but inchned to spht 



the apex of the leaf (fig. 13). The spine area is unusually short, 

 about 18 to 25 per cent of the blade length, and the spines are 

 rather long, slender and acute; 

 where considerably shaded 

 they are inclined to be weak 

 and soft. The spines merge 

 into narrow spike pinnse, fol- 

 lowed by ribbon pinnse 24 to 

 30 inches long and one-haK to 

 five-eightlis of an inch wide, 

 which are frequently pendu- 

 lous, but soon give place 



the 



blade to those of normal form, 

 18 to 24 inches long and 1 inch 



/08 



up 



The axial divergence of 



the pinnse is, for the antrorse 

 class, only about 20° to So"" 



Fig. 13.— Cross sections of the rachis of a Hayany dat« 

 leaf, sbowing outliDcs at diilercnt distauccs from base 

 to apex. 



near the base, becommg 45° or 50° toward the apex. The introrse 

 and retrorse classes diverge more strongly, in some leaves to 00° or 

 65 °. In divergence from the plane of the blade the antrorse pinnse 



