MUTATIONS, VARIATIONS, AND RELATIONSHIPS OF THE OENOTHERAS. 7 1 



OENOTHERA OAKESIANA mihi. 



This plant was presented to Professor Gray many years ago as a well -characterized and 

 distinct species, which I still consider it. I discovered it in the medical colleges in New 

 Haven, Connecticut, in 1827. In 1831 I sowed its seed with those of the ordinary variety. 

 The differences are as follows: 



(1) If raised from seeds sown in the spring it is annual, the common variety by its 

 side being biennial. 



(2) The leaves of the first year, when biennial, are much narrower. 



(3) The pubescence throughout is soft-appressed, that of the other being coarser and 

 spreading. 



(4) The points of the calyx are always spreading, in the other appressed. 



(5) The capsule is longer and more taper. 



(6) The ripe seeds are larger. 



I have found but two other localities, namely, on sides of the railroad north of Norton, 

 Massachusetts, and another, same situation near Apponong Depot, Rhode Island. Also, it 

 is well naturalized in Uxbridge, Massachusetts, from my seeds. 



UXBRIDSE, sth Sept., 1878. J. W. ROBBINS. 



The plants from the New York Botanical Garden were first noticed by Dr. 

 MacDougal late in the summer of 1904. They grew not far from the embank- 

 ment of the Harlem Division of the New York Central Railroad and were 

 quite abundant, though not covering a very widespread area. With them 

 were associated a number of 0. biennis, the latter in that particular spot, how- 

 ever, being not as abundant as elsewhere in the garden. Rosettes were 

 obtained of the 0. oakesiana and the plants raised from them the following 

 summer were in every way similar to the wild plants, and formed the basis of 

 these notes on the species. Plate 17 was photographed from a specimen 

 growing wild in the New York Botanical Garden. 



OENOTHERA PARVIFLORA LINN^US. 



Oenothera parviflora Linnaeus. Syst., ed. 10: 998, 1759. 

 Onagra parviflora Moench. Meth. Supp!., 287, 1802. 



Seedling about 6 weeks old. Rosette 2.5 to 3 cm. in diameter, rather loose and irregular, 

 blades of the leaves ovate or ovate-spatulate, glabrate, ciliate. 



Rosette about 3 months old. Leaves finely pubescent on both surfaces, less so above; 

 blades various, those of the earlier leaves narrowly oblong or oblong-spatulate, varying to 

 oblong-obovate, 6 to 10 cm. long, the larger ones 2.5 to 3 cm. wide, approximately and 

 shallowly denticulate, obtuse or nearly so at the apex, gradually narrowed to the base of the 

 margined petiole, which is very early streaked with red or pink. 



Mature rosette. Leaves long and slender, spreading flat on the ground ; blades lanceolate, 

 or oblong-lanceolate, acutish, irregularly and strongly denticulate, more deeply toothed at 

 the long, tapering base, dark green and shiny, sparingly mottled with red, sparingly puber- 

 ulent above, more so and paler beneath, 15 to 30 cm. long, 3 to 5 cm. wide; petiole white, 

 8 mm. wide, margined to base, distinctly pink or red ringed most of its length (plates 18 

 and 20). 



Adult plant. Central stem not always maturing the first season when forced. Lateral 

 branches of annual rosette stout and angled, pubescent with spreading hairs; leaves 

 resembling those of the rosette in color, texture, and pubescence; blades oblong to oblong- 



