IDENTIFICATION OF CHERRY VARIETIES 3 



nursery trees budded on Mahaleb stock and growing side by side in the station 

 nursery at Amherst. 



The sources of bud-wood for the several varieties include the New York Agri- 

 cultural Experiment Station at Geneva, the Ohio Agricultural Experiment Sta- 

 tion at Wooster, and the Ontario Horticultural Experiment Station at Vineland, 

 in addition to our own bearing orchards. Every effort has been made to establish 

 the identity of the varieties used in this study. 



The Constancy of Characters 



It is to be expected that at least some of the characteristics by which one 

 variety differs from another will be affected by the environment in which the 

 trees are growing. Consequently, some differences will be found between trees 

 growing in Massachusetts and those of the same variety growing in Maryland, 

 Michigan, or some other reg'on, as well as between trees growing m soils of differ- 

 ent levels of fertility. The effect of environment, however, is one of degree rather 

 than kind. Thus, the actual amount of pubescence on the petiole of a variety 

 might be somewhat less under one set of growing conditions than under another; 

 but, since the presence or absence of pubescence is doubtless a genetic character, 

 it would not be expected that a variet\' would have pubescence in one section of 

 the country and be completely devoid of it some place else. Furthermore, even 

 when a character is affected somewhat by environment, the several varieties main- 

 tain their relative order for that character regardless of where grown. While the 

 characters as herein described' are those of trees grown at one place, the writer 

 has examined nursery cherry trees in widely separated regions over a period of 

 about fifteen years and has found these characters to be sufficiently cor^stant to 

 permit their use in the identification of varieties. 



When to Examine Cherry Trees 



Not all of the distinguishing characteristics of a variety can be observed at any 

 one time. For example, color of the \-oung tip leaves and amount of pubescence 

 on the leaf petiole can be observed most readily fairlj' earlj' in the season while 

 length growth is still active. On the other hand, bud, bark, and lenticel charac- 

 ters become more distinctive near the end of the growing season as the wood 

 approaches maturity. Yet leaf spot, insect injury, spray material, and dust may 

 obliterate some of the most valuable characteristics of the leaves in late summer. 

 Two-year trees show certain characters which cannot be found in one-year whips; 

 and conversely, some characters are more evident on one->ear whips than on 

 two-year trees. 



It has been the experience of the writer and his colleagues that sweet cherries 

 can be examined best while the tips are still making active growth. With most 

 varieties the one-year whip is as easily identified as the two-j'ear tree. However 

 with the sour cherry varieties. Early Richmond and Montmorency, there are 

 important lenticel differences which seldom are found on one-vear trees. 



How Varieties Differ 



In the accompanying illustrations, specimens have been chosen which emphasize 

 or even exaggerate the character in question, because it is recognized that cuts 

 in a publication seldom do justice to the object. Furthermore, it should be real- 

 ized, since living plants are to be considered, that not all individuals or all parts 

 of a single tree may possess the character in question to the degree illustrated. 

 Yet these are the characters by which one variety of cherry may be distinguished 

 from another. 



