INHERITABLE VARIATIONS IN THE YELLOW 

 DAISY (RUDBECKIA HIRTA)i 



Albert F. Blakeslee 



Station for Experimental Evolution 



Variations in the following characters have been found in the 

 wild yellow daisy: absence of rays and their presence in rather 

 definite numbers from 8 to 30 and to perfectly double forms; 

 width of rays; diameter of head from i to 53^ inches; color of rays 

 from pale straw color to deep orange; relative intensity of color in 

 inner half of ray forming a lighter or darker ring; different in- 

 tensities of mahogany color at base of ray on upper side; mahogany 

 on under side of ray; constriction of ray at tip, at middle, or at 

 base — those constricted at tip, either rolled in or rolled out to 

 give the "cactus" type seen in dahlias — those constricted at 

 base without change in color or characterized by lighter color or 

 by presence of black pigment on constricted areas; transformation 

 of rays into tubes giving "quilled" type; the position of rays, 

 bending upward, horizontal, reflexed, straight or variously twisted; 

 the shape and size of disk; the color of disk from yellowish green 

 through several grades of purple to almost black; vegetative 

 characters such as height, branching, size and shape of leaf, 

 fasciations, etc. 



Evidence from the distribution of the variants in nature and 

 from their reappearance in sowings from open-pollinated heads 

 shows that most, if not all, these variations are inherited. The 

 basal splash of mahogany on the ray seems to be inherited as a 

 simple Mendelian dominant, while another red blotching is in- 

 herited as a recessive. Other characters are being investigated. 



1 Abstract. The paper was illustrated by living specimens. 



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