SOME SEGREGATES OF OENOTHERA. 137 



Oenothera ammophila Focke. 



Briefly described in Abh. Nat. Ver. Bremen. 18: 182-186. 1906. 



From the coast near Bremen, Germany. 



Rosette leaves small, long, narrowed into a petiole, both 

 sides thickly clothed with appresscd hairs. The rosette re- 

 mains after the stem is formed in the second year. Stems 

 .5-1 m. high. Stem and capsules covered with short, club- 

 shaped (?) hairs. Also scattered long pointed hairs which 

 arise from reddish protuberances. These are evidently the 

 same two types of hairs found in 0. Lamarckiana and its 

 derivatives and in 0. biennis. The petals are similar to those 

 of 0. biennis but smaller, slightly crenate. It is like 0. mu- 

 ricata in having petiolate rosette leaves and small stem 

 leaves, in its pubescence and the crenate petals; but it 

 differs in having large flowers and longer sepals. It also re- 

 sembles 0. muricata in that the rosette of the previous year 

 remains after the stem is formed in the second year. The 

 cultures of MacDougal (Carnegie Pub. no. 81. 1907) have 

 shown that 0. ammophila may produce bud reversions to 

 0. biennis, which makes it probable that 0. ammophila is a 

 hybrid between 0. biennis and some other form. The leaves 

 are smaller and narrower than in 0. biennis. 



August 18, 1909. 



