76 De Vries : Atavistic Variation in Oenothera 



Oenothera cruciata Nutt. or Onagra cruciata (Nutt.) Small, as 

 it is also called, has been described and figured in Britton and 

 Brown's " Illustrated Flora of the Northern United States, Canada 

 and the British Possessions " (2 : 485. 1897). It is a rare plant, 

 found wild from Vermont to New York and Massachusetts, and 

 ascends to 2,000 feet in the Adirondacks. It is described as being 

 annual and flowering from August to October. It may readily be 

 recognized, even without flowers, by the narrowly oblong or 

 oblanceolate leaves and the purple color of the nerves and the 

 stem. The flowers are as small as those of 0. muricata, but the 

 spikes are much more slender and the fruits are less broad. In 

 all these characters the European plants correspond exactly with 

 the description given by Britton and Brown. The petals of the 

 American type are linear instead of being broad and obcordate as 

 in the allied species. 



As yet I have not had an opportunity to cultivate the original 

 wild species, but I hope to be able to do so next year, as I have 

 obtained seeds from the Adirondacks through the kindness of Dr. 

 D. T. MacDougal, of New York, and Dr. B. L. Robinson, of Cam- 

 bridge, Mass.* 



Dr. MacDougal had also the kindness to ask Dr. Britton about 

 an eventual variability of the petals, but the celebrated author of 

 the Illustrated Flora informed him that Oenothera cruciata does not 

 make broad petals in America. 



This is the essential point. For in all the cultures I have as 

 yet been able to make from seeds of this species, sent to me from 

 different botanical gardens in Europe, I found the form of the 

 petals to be varying in a high degree, so as to reach, in many in- 

 •dividuals, the same outline as is presented by the petals of the 

 allied species, 0. biennis, 0. muricata and others. 



For this reason, I presume that our plants are not the typical 

 ■0. cruciata of Nuttall, but a variety, which perhaps has been pro- 

 educed from it in Europe. Therefore I have called my plants 0. 

 cruciata varia, merely in order to distinguish them from the pure 

 species. How this variety may have originated of course I do not 

 know. Two possibilities present themselves. The one is by mu- 



* Seeds from different localities would be always very welcome to me, as the plant 

 may be in a mutable state in some districts, while it is not so in others. 



