4S6 The Systematic Value of the New Species. 



O. suavcolcns. This will be sufficient to show that the 

 differences between the former are greater than those 

 between the latter. A study of the other old species 

 would obviously only serve to bear out this conclusion. 



Let us begin with the seedlings. They fall into two 

 groups. O. biennis and O. Lamarckiana have broad 

 leaves (Fig. 102 A), O. muricata, 0. cruciata and 0. 

 suave olens narrow ones (Fig. 102 B). 



These differences can be seen particularly well in 

 very young rosettes ; but when the leaves begin to grow 

 quickly as they do in June they all become longer and their 

 distinguishing feature, therefore, less striking (Fig. 103), 



Fig. 102. Seedlings. A, of Oenothera biennis L. ; B, of 

 O. muricata L., two months old. 



only however to become quite clear again later on. I 

 have often grown rosettes of various new and old spe- 

 cies in rows, close to one another, in order to compare 

 10-20 or more individuals of the same age and under the 

 same conditions. O muricata and 0. scintillans differ 

 most widely from the normal in the narrowness of their 

 leaves ; in both of them the leaves are smooth and shiny ; 

 in the former however they are pale green and long, in 

 the latter dark green and short. O. ruhrinervis, O. 

 suaveolens and O. hirsutissima have wavy crumples and 



