16 



MASS. EXPERIMENT STATION BULLETIN 421 



can be described as dull as in Clairgeau, semi-glossy as in Clapp Favorite, or 

 glossy as in Dana Hovey (Figure 11). Of course, there are intermediates between 

 these three conditions. Also, the glossiness of the different leaves on one variety 

 may vary. For example, Ovid leaves are described as semi-glossy to moderately 

 dull, and those of Comice as semi-glossy to dull. 



The value of leaf color in variety identification is considerable, despite the fact 

 that amount and shade of color may be moderately to greatly influenced by 

 nutritional conditions. It is common knowledge, for instance, that the foliage 

 of well-fertilized nursery trees is a deeper green than that of trees growing on 

 poor soil, lacking in nitrogen. Nevertheless, the general leaf color is one of the 

 first characteristics to be taken into consideration when examining nursery 

 trees for trueness-to-name. An abrupt color change in a nursery row may often 

 indicate a change of variety. For example, the average color of well-developed 

 leaves on vigorous shoots may be rather light green as in Wilder, medium green 

 as in Caywood, dark green as in Willard, light yellowish green as in Sheldon, 

 medium yellowish green as in Anjou, dark yellowish green as in Bartlett, or mot- 

 tled light yellowish green as in Worden Seckel. The development of reddish 

 coloration in late summer and fall varies with variety. Douglas leaves often 

 turn red earlier and more uniformly than those of other varieties. Louise, 

 Comice, Dumont and a few others also tend to develop more or less red in their 

 foliage. On the other hand, Gorham and Lincoln foliage usually remains green 

 until cold weather. Other varieties remaining mostly green include Lawrence 

 and Patten. 



Figure 12. Serrations. 



BANTAM — Moderately fine, setose serrate, moderately regular, distinct, prominent 



BARTLETT — Fine, serrate, moderately shallow, regular 



OVID — Moderately coarse, very shallow, irregular, often indistinct 



SHELDON — Rather deep, serrate, slightly hooked, regular, prominent 



CLYDE — Coarse, dull serrate, slightly hooked, rather irregular 



The leaf serrations or teeth along the leaf margins are worth noting (Figure 12), 

 Serrations may vary from fine as in Bartlett to coarse as in Ovid; very shallow 

 as in Ovid to rather deep as in Sheldon; dull serrate as in Clyde to very sharply 

 or setose serrate as in Bantam to hooked as in Sheldon; regular as in Bartlett 



