360 BOTANICAL GAZETTE [MAY 
was in the same condition of mutability at the time of its first 
appearance as it is now, is of course a different question.* 
Summing up the results of this historical investigation, we may _ 
1. Oenothera Lamarckiana Ser. is represented by specimens in 
the herbaria of Lamarck, Pourret, and Micuavux (pls. XVIL- 
XIX), and is, so far as this material enables us to judge, at the 
present time exactly the same plant as it was at that period. It 
has come 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 MicHavx 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 O. 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 MicHavux himself or by some other botanist of 
is period. 
AMSTERDAM 
EXPLANATION OF PLATES XVII-XIX 
Plate XVII 
Oenothera grandiflora Lam. (O. Lamarckiana Ser.): the authentic specimen 
in the herbarium of Lamarck, two-thirds natural size, referred to as 4 
text; in the left upper corner a bunch of flower buds of my culture of 1913, 
dried and pressed, is given for comparison, and photographed togeth 
the main specimen. 
er with 
Plaie XVIII 
Oenothera grandiflora Lam. (O. Lamarckiana Ser.): the specimen hen 
herbarium of Father Pourret, one-third natural size; on the label is wr! 
Onagra vulgaris grandiflora Spach. 
3 Uber die Dauer der Mutationsperiode bei Oenothera Lamarckiona- i 
Deutsch. Bot. Gesells. 23:382. 1905. 
