AN ALBINO RUDBECKIA 



By Willard N. Clute. 



IT is well known that albino forms of yellow-flowered species 

 are exceedingly rare. It is true that in t3rpically yellow- 

 flowered genera, such as the golden-rod or the sunflower group, 

 we may occasionally find species with white or whitish flowers, 

 but within the limits of the species, a yellow flower rarely has 

 a pure white form. On the contrary blue and pink flowers 

 frequently produce pure white flowers. 



A partial explanation of this condition may possibly be 

 found in the manner in which color is borne in different flow- 

 ers. Pink and blue flowers are usually due to colored cell 

 sap ; yellow flow^ers nearly always owe their hue to certain col- 

 ored bodies in the cells called chromoplasts. It is a curious fact 

 that the yellow coloring matter of the chromoplasts becomes 

 red with slight changes and in consequence it is often easier to 

 produce a red flower from a yellow one than it is tO' produce a 

 true albino. In cases where albinos of red flowered forms are 

 known, it will usually be found that the red color is due to col- 

 ored cell sap and not to chromoplasts. Chromoplast flowers 

 usually have a tinge of yellow. 



In the light of the foregoing considerations, the occur- 

 rence of a very pale form of the common black-eyed Susan 

 {Riidbcckia Jiirta) is of suflicient interest to be recorded. In 

 all respects it corresponds to^ the priuiuliniis forms recently 

 named in related genera. To facilitate any further reference 

 to it in print the following name and description will be 

 useful : 



