THE AMERICAN BOTANIST 



63 



should be of much interest to seedsmen and others who are 

 desirous of securing strains that will not "revert" to a less de- 

 sirable parent. 



Oenothera Lamarkina a Hybrid. — Probably every- 

 body knows by this time that a new theory of evolution, called 

 the Mutation Theory, has arisen to shake our confidence in a 

 too literal interpretation of the theory of the origin of species 

 for which Darwin and Wallace were largely responsible. The 

 new theory rests on a considerable basis of experimental proof 

 but the plant with which the most astonishing feats have been 

 accomplished, Oenothera Lamar kiana^ is somewhat under sus- 

 picion. Though described as a species and until recently so 

 considered, it has never been found wild except in a certain 

 small area in Holland where it is known to be an exotic. It 

 is from this plant that a number of forms quite different from 

 the parent plant have been produced without intergrading vari- 

 ations, which fact has played an important part in the interpre- 

 tation of the mutation theory. If the plant is a true species, 

 then the production of these forms is remarkable, but if the 

 parent plant happens to^ be a hybrid, the production of different 

 forms is nothing out of the ordinary ; in fact, is to be expected. 

 As the investigation of the evening primrose (Oenothera) goes 

 on, it becomes more and more apparent that O. Lamarkiana is 

 really a hybrid between other species, possibly between 

 O. grandiflora of the Southern States and our common form 

 of waste grounds, O. biennis. This fact makes the production 

 of new forms in this species less wonderful, but it does not 

 militate against the mutation theory itself, for the grower of 

 plants may see mutations of various kinds in any large collec- 

 tions of a given species if he cares to look for them. 



Shadbush Flowers Ill-Scented. — One of the species 

 of shadbush (Amelauchier) has blossoms that are quite ill- 

 smelling. The shrub is of medium size and grows on pine 

 plains, perhaps elsewhere. Which species is it? I have failed 



