New Species of Oenothera 531 



may be discerned among the others, some weeks 

 before the flowers begin to show themselves. 



But the character by which the plants may 

 be most easily recognized from a distance in the 

 field is the failure of the fruits. They were 

 found nearly every year in varjdng, but always 

 small numbers. 



Leaving the short-styled primrose, we come 

 now to the last of our group of retrograde va- 

 rieties. This is the 0. nanella, or the dwarf, and 

 is a most attractive little plant. It is very short 

 of stature, reaching often a height of only 20- 

 30 cm., or less than one-fourth of that of the par- 

 ent. It commences flowering at a height of 10- 

 15 cm., while the parent-form often measures 

 nearly a meter at this stage of its development. 

 Being so very dwarfed the large flowers are all 

 the more striking. They are hardly inferior 

 to those of the Lamarclciana, and agree with 

 them in structure. When they fade away 

 the spike is rapidly lengthened, and often be- 

 comes much longer than the lower or vegetative 

 part of the stem. 



The dwarfs are one of the most common mu- 

 tations in my garden, and were observed in the 

 native locality and also grown from seeds saved 

 there. Once produced they are absolutely con- 

 stant. I have tried many thousands of seeds 

 from various dwarf mutants, and never ob- 



