236 



PEAR GROWING IN CALIFORNIA. 



LEAF CHARACTERISTICS OF VARIETIES. 



The studies made during the eourse of preparation of this bulletin 

 revealed some interesting facts regarding the leaf characteristics of 

 species and varieties of pears. Each species, as would naturally be 

 expected, possesses an entirely different form of leaf, by means of which 

 its identification wherever the species might be found would be practi- 

 cally certain. The variation is much greater than would be supposed by 

 those who are not familiar with a number of different species. The 

 leaves shown in Figs. 4 and 5 illustrate this point clearly. In Pyrus 



Fig. 4. Leaf of Pyrus heterophylla. 



Fig. 5. Leaf of Pyrus variolosa. 



lieteropJiylla is found the extreme type of lobed leaf. This leaf has 

 little to suggest that it belongs to a pear tree. The other has more of the 

 characteristic shape of the cultivated varieties. The serration is more 

 prominent in most of the wild species than in our cultivated varieties. 

 The serration furnishes one of the important identification character- 

 istics. In some varieties there occurs a small, regular serration as in 

 Bartlett ; in others it is irregular. Certain varieties, e. g., Winter Nelis, 

 Anjou and Bosc, have practically no serration, although the leaf 

 margins may be more or less wavy. The general shape of the leaf 

 differs markedly with different varieties and while there is a wide varia- 

 tion between individuals on the same tree, it is not difficult to pick the 

 common shape that is characteristic of the variety. The apex and stem 

 also furnish distinguishing characteristics. Here, again, the variation 

 is sometimes confusing but the characteristics that most of the leaves 

 possess soon become fixed in one's mind as he studies them. Contrary 

 to expectation, the length of petiole is so variable that little stress can 

 be laid upon this characteristic as an aid in the identification of varie- 

 ties. For example, the length of petioles of leaves of the Winter 

 Nelis variety collected at Niles and at Lakeport varied from 



