THE PROBABLE ORIGIN OF OENOTHERA LAMARCKIANA SER. 593 



down to us, through more than a century, as unaltered and as 

 constant as true species usually do, 



2. It has been a component of the flora of the eastern United 

 States, where Michaux collected it and whence Lamarck derived 

 his specimen, 



3. At the present time it is a component of the flora of England 

 and is as well established in that country as is 0. biennis in different 

 parts of Europe. 



4. The strain which is now in cultivation, and which was intro- 

 duced into the trade about the middle of the last century, was 

 probably derived from some wild English locality, which itself 

 may have come from an introduction into Europe of the seeds 

 collected either by Michaux himself or by some other botanist of 

 his period, 



Amsterdam. 



Explanation of Plates I-III. 



Plate I. 

 Oenothera grandiflora Lam. (0. Lamarckiana Ser.): the authentic specimen in the her- 

 barium of Lamarck, two-thirds natural size, referred to as A in the text; in the left upper 

 corner a bunch of flower buds of my culture of 1913, dried and pressed, is given for com- 

 parison, and photographed together with the main specimen. 



Plate II. 

 Oenothera grandiflora Lam. (0. Lamarckiana Sen): the specimen in the herbarium of Father 

 Pourret, one-third natural size; on the label is written Onagra vulgaris grandiflora Spach. 



Plate III. 

 Oenothera Lamarckiana Ser. in the "Herbier de I'Amerique septentrionale" of Andre Michaux, 

 collected about 1800 in the eastern parts of the United States: A, top of spike photographed 

 and reproduced about natural size; B and C, the whole specimen of Michaux, consisting of 

 two parts, reduced about one-half ; all three figures photographed for me by Dr. L. Blaringhcm ; 

 in the reproduction the narrow bands of paper used to fix the specimen to its sheet and seen 

 on the photographs have been omitted. 



(The Botanical Gazette, Vol. XVII, May i()i4> P- 345-) 



