Genetical Studies on Oenothera. V. 



173 



DE Vries ('13, p. 37) reports the presence of closely related races at a 

 number of stations in the middle west. I am informed that the application of 

 the name Oenothera muricata Linnaeus is more difficult than that of 

 Oenothera biennis Linnaeus, but it will be most unfortunate if the name 

 cannot be held for this plant wliich has taken and will continue to take 

 a very important place in the literature of experimental morphology. 



Fig. 4. Rosette of muricata, nearly mature, sliowing the loose cluster of narrow- 

 elliptical, plane leaves. Contrast with Fig. .3, biennis. 



To bring the chief taxonomic features of 0. biennis and 0. muricata 

 clearly before the reader I shall first describe the two species in parallel 

 columns selecting the characters that stand in sharpest contrast so that 

 these may be compared with one another and with the conditions presented 

 by the reciprocal crosses. The descriptions are of plants started under 

 glass during the winter and in the spring set out as rosettes in the 

 experimental garden. 



