Oenothera Oblonga. 345 



(Fig. 71 B) which is always found in all the plants of 

 this species. The culture in question did not contain 

 a single plant bearing flowers on a lateral stem, with the 

 exception of the plant referred to. 



At the time when the plant is about to flower (Fig. 

 44, p. 233) the flowering spike is still densely clothed 

 with leaves. Higher up, the bracts become shorter. The 

 fruits likewise do not attain the size of those of 0. La- 

 marckiana ; and we get in this way another very striking 

 character which can be well seen by comparing Plate VI 

 with Plate I. The ripe fruits hardly attain a third of 

 the length of those of O. Lamarckiana. As a result of 

 this, the seeds are often bad and developed in very small 

 quantity so that all that can be hoped for is a very meagre 

 harvest at the best. 



Biennial plants are much better in this respect; they 

 are more robust and bear numerous, strong, though small, 

 fruits which contain an abundance of seed. These fruits 

 are not much longer than those of the annual plants but 

 much stouter, rather like those of 0. lata. 



When grown under more favorable conditions the 

 annual as well as the biennial plants develop a certain 

 number of lateral stems from the axils of the radical 

 leaves, such as have already been figured in the case of 

 a mutation from the /a/a-family (Fig. 50, p. 284). But, 

 even so, the main stem itself remains unbranched, a pecu- 

 liarity which can best be seen by comparing such a plant 

 with O. nihrinervis (Fig. 49, p. 282). 



There is not much to be said about the flowers and 

 buds of O. oblonga (See Plate VI). They have the 

 same form as those of the parent species; but in cor- 

 respondence with the greater delicacy of the whole plant 

 thev are a trifle smaller. 



