526 



Davis: Lamarck's evening primrose 



O. grandiflora Solander and Lamarck's 



PLANT 



Flowering stems generally with numer- 

 ous approximate branches. 



Stems green above, reddish brown below, 

 the papillae at the base of long hairs 

 colored like the stem. 



Leaves of upper foliage lanceolate, 

 rarely broad, with distinct petioles. 



Inflorescence more open, with narrow, 

 petioled bracts. 



Buds not stout, with much attenuated 

 sepal tips. Sepals puberulent, some- 

 times sparsely pilose. 



Flowers with a long delicate hypan- 

 thium. Petals 3-3.5 cm. long. Stig- 

 ma lobes above the tips of the anthers. 



0. Lamarckiana FROM THE CULTURES OF 

 De Vries 



Flowering stems sparsely branched or 

 not at all. 



The papillae at the base of the long hairs 

 colored red so that the green stem 

 appears punctate with red dots. 



Leaves of upper foliage ovate-lanceolate, 

 sessile or almost sessile. 



Inflorescence more close, with sessile 

 bracts broad at the base. 



Buds stout, with shorter sepal tips. 

 Pubescence of sepals a heavy puber- 

 ulent and pilose covering. 



Flowers with a stouter hypanthium. 

 Petals in some races 4-4.S cm. long, 

 in others 2.5-3 cm. long. Stigma 

 lobes in the large-flowered types above 

 the tips of the anthers, in the smaller- 

 flowered forms at about the level of 

 of the anther tips. 



There is another sheet in the herbarium of the Museum d'His- 

 toire Naturelle which is without a name but bears in the hand- 

 writing of Lamarck: "d'Am^rique sept. Tige rameuse, haute de 

 3^4 pieds." Both M. Gagnepain and Miss Eastwood report that 

 this sheet is similar to that of Lamarck's plant which we have 

 described above and shown on plate 37. The history of the sheet 

 is apparently not known and I have no evidence that it can safely 

 be associated with the specimen upon which Lamarck undoubtedly 

 based his description. Nevertheless, this sheet may be closely 

 related to or even a duplicate of the specimen that served as the 

 type for the descriptions of Lamarck and Seringe. 



In summary it may be said that the specimen, which we must 

 consider the type of Oenothera Lamarckiana Seringe, presents no 

 characters in clear form that are not those of 0. grandiflora 

 Solander. In not one of the contrasted characters discussed 

 above does the specimen agree with the Lamarckiana of De Vries's 

 cultures. The only points in which De Vries's Lamarckiana may 

 be said to resemble this specimen are the size of the petals and 

 the position of the stigma, which in the large-flowered forms of 

 Lamarckiana is above the tips of the anthers ; these are characters 

 which grandiflora and De Vries's Lamarckiana have in common. 



