1913]  Bartlett,— Systematic Studies on Oenothera,—II 51 
conform to what is usually called, in a collective sense, Oe. biennis. 
They differ only in flower color, one having flowers of a lighter color 
than the other. The light-colored form has only become abundant 
in recent years, through its prompt occupation of a newly created 
habitat, the rights of way of the more recently constructed railroads. 
It has long occurred at many localities in Holland, however, and may 
be identified with reasonable certainty with the var. a of Linnaeus' 
Oenothera foliis ovato-lanceolatis denticulatis, floribus lateralibus in 
summo caulis (Hort. Cliff). To be sure Linnaeus assigned this 
plant no name of his own, citing merely two polynomials of Tourne- 
fort's. One of them, however, Onagra latifolia, flore dilutiore Tourn. 
was merely a new name for Hermann's Lysimachia corniculata non 
papposa, Virginiana, major, flore sulphureo (Hort. acad. Lugd.-Bat. 
Catalogus, 1687) which was grown and described at Leyden half a 
century before Linnaeus’ residence in Holland. We are therefore 
justified in treating the lighter-flowered plant of Holland as a variety 
of the other, which is to be regarded as the type of Oenothera biennis. 
The two plants, according to Professor de Vries, differ in the one 
character only. 
It would hardly have been worth while to give in so much detail 
the reasons for selecting the common plant of Holland as typical 
Oenothera biennis but for the fact that certain botanists do not seem 
to realize that such a selection should be made according to principle. 
Dr. Britton, for instance, seems to have been able to select from 
among the American Oenotheras one which he arbitrarily pronounced 
to be Oenothera biennis “in the strictest sense." ! 
In a recent paper, Dr. Gates? has mentioned a specimen in the 
Linnaean Herbarium which he calls “the type specimen of Linnaeus’s 
Oenothera biennis in the Species Plantarum." It would seem to be 
unnecessary to point out that Linnaeus had no * types" in the modern 
sense, and that the specimens in the Linnaean Herbarium cannot be 
1'5,...a number of plants of Onagra biennis (in the strictest sense), growing 
in uncultivated land in the New York Botanical Garden in 1903, were selected to form 
the basis of a pedigree culture in 1904."  Macdougal, Vail, Shull, and Small; Mutants 
and Hybrids of the Oenotheras, p. 9, 1905, “Parental individuals were selected and 
verifled by Dr. N. L. Britton in 1903, and from the seeds furnished by them the 
plants were grown which furnished material for the descriptive diagnosis published 
in a previous paper (Macdougal, Vail, Shull and Small, 1905). "This is not the species 
growing wild in Europe and cited by de Vries in his 'Mutationstheorie.'" Macdougal, 
Vail, and Shull: Mutations, Variations and Relationships of the Oenotheras, p. 56, 1907. 
These quotations refer to the same culture, 
2 Gates, R. R.: Mutation in Oenothera. American Naturalist xlv (1911) pp. 577- 
606. 
