THE DATE PALM. 



3. The stem of the tree is cylindrical. Unlike the stems 

 of most trees which increase in thickness prac- 

 tically throughout their whole life, the stem of 

 the date palm does not increase in thickness after it has developed 

 a full crown of functional leaves. This is attained by the time 

 that a distinct stem covered with withered leaves or where 

 these have been pruned away their bases can be distinguished 

 above the level of the ground. The age of an adult date palm, 

 therefore, cannot be told from the thickness of its stem. Even 

 the length of the stem and the number of old leaf bases on it are 

 not very accurate indications of age, as a palm in good conditions 

 of soil and climate grows very much faster and matures more 

 leaves per year than those in adverse conditions. 



The stem when opened and examined by the naked eye 

 (see illustration No. 7 opposite) is seen to be composed of a vast 

 number of tough string-like fibres commonly over | millimeter 

 in thickness lying apparently close together and mostly running 

 lengthwise in the stem. The string-like fibres are the vascular 

 bundles (sap-conducting tissues) of the plant (see illustration 

 No. la, page Qb) surrounded by a good deal of hard tissue 

 (sclerenchyma). The vascular bundles are connected with the 

 sap-conducting] tissues of the root. In the stem they give off 

 branch bundles occasionally which can be traced across the 

 -vertical ones in an upward slanting direction into the leaf 

 bases. This mass of tough strings is held together by a 

 matrix of cellular tissue which near the periphery of the stem 

 becomes so much lignified (thickened and toughened by a deposit 

 of lignin) that it is almost as tough and hard as the fibres 

 themselves, the whole making a stem far exceeding those of 

 ordinary trees in strength and resilience. When the palm is 

 cultivated, the leaves are pruned off near their bases after they 

 begin to lose their vigour, but in the wild state these leaves simply 

 bend downwards when they wither, and remain attached to the 

 tree for many years later. Whether the old leaves have been 

 left on the tree or pruned away, the stem proper remains closely 

 and permanently covered with the hard old leaf bases. This 



