Incipient Species. 



423 



lans. And last of all, two rosettes from seeds of Oeno- 

 thera lata fertilized by O. biennis. 



I obtained altogether four flowering plants of O. siib- 

 ovata, one in 1889 and 1895, and two in 1899. The 

 former arose from Lamarck- 

 iana-SQcds, was annual, freely 

 branched but dwarfed. It de- 

 veloped not only a main stem, 

 but lateral ones from the axils 

 of its radical leaves. Only a 

 single one of these latter bore 

 normal flowers like the parent 

 species. The other lateral 

 branches and the main stem 

 however were quite sterile. In- 

 stead of flowers in the axils of 

 the leaves there were little green 

 leafy shoots (Fig. 96) which 

 gave the plants a most singular 

 appearance.^ 



The mutant of 1895 arose 

 from the Larnarckiana-isimily 

 and flowered in August of its 

 first year. The flowers were of 

 the same form as those of the 

 parent species ; but, in corre- 

 spondence with the greater deli- 

 cacy of the plant, smaller. Later 

 on, however, it became stronger and the flowers which 

 were borne on its lateral branches at the end of Sep- 

 tember were quite as large as those of Laiiiarckiana. 



* This foliation was due to internal causes and not a pathological 

 virescence like that which may be brought about by parasites (Pliy- 

 toptus, plant-lice, etc.). I have occasionally seen examples of this 



Fig. 96. Oenothera sub- 

 ovata. A barren stem, 

 1889. 



