12 THE CHERRIES OF NEW YORK 



all are more or less variable, pubescence especially so, this character 

 being too often relied upon in descriptions by European botanists and 

 pomologists. 



Leaf-buds vary greatly in different species in size, shape, color of 

 the buds and of their outer and inner scales and in the outline of the 

 scales. The angle at which the bud stands out from the branchlet is of 

 some taxonomic value. Vernation, or the disposition of the leaf-blade in 

 the bud, is a fine mark of distinction in separating the cherry from other 

 stone-fruits and while all cherry leaves are supposed to be conduplicate, 

 that is, folded by the midrib so that the two halves are face to face, yet 

 there are slight but important differences in the conduplication of the 

 leaves in both species and varieties. The manner of bearing buds — 

 whether single, in pairs, or in rosettes — must be taken into account, with 

 species at least, and differences in shape and position of leaf and fruit- 

 buds must be noted. 



Leaves in their season are very evident and either collectively or 

 individually are valuable determinants of species and varieties. Fruit- 

 growers take little note of leaves, however, though they should be taken 

 into practical account, since their size and number often indicate the 

 degree of vigor. The variability of leaves is usually within limits easily 

 set and occurs most often in young plants, in extremes of soil and 

 climate, and on very succulent growths or water-sprouts. Leaf-size is the 

 most variable character of this organ but is yet dependable in separating 

 several species, as, for example. Primus avium from Prunus cerasus, the 

 leaves being very much larger in the former than in the latter species. 

 Leaf -forms are very constant in species and varieties, hence especially 

 valuable in classification. 



Much care has been taken to illustrate accurately the size and form 

 of cherry leaves in the color-plates in this text but it is impossible to 

 reproduce by color-printing the tints of the leaves, though these are quite 

 constant in both species and varieties. 



Other characters of leaves taken into account in describing cherries 

 are thickness, roughness, and pubescence, all of which are somewhat 

 variable, being greatly influenced by climate and soil. Quite too much 

 stress is laid upon the value of pubescence on leaves in determining groups, 

 unless comparisons can be made between plants growing in the same 

 habitat. Possibly more important than any other part of the leaf-blade, 

 in the study of species at least, is the margin. This in the cherry is 



