Presumptive Mutations in Wild & Cultivated Plants 71 



south as Maine and Vermont, where type and variety sometimes 

 occur together in the same colonies. 



The sunflowers of the middle Western States of America 

 are a polymorphic group represented by great numbers of 

 individuals. In 1910 a single mutant of Helianthuslenticularis with 

 red instead of yellow rays was found at Boulder, Colorado by 

 Cockerell (1912). It proved to be heterozygous and has since 

 behaved as a simple Mendelian dominant in crosses with other 

 species. In the history of its origin it forms an exact parallel to 

 (Enothera rubricalyx. Cockerell (1915) has since studied many 

 elementary forms in the wild species. He quotes from Church the 

 history of the cultivated H. annuus, L. which is a gigantic non- 

 branching form. Like maize, its origin in cultivation is only a 

 matter of conjecture. Its seeds furnished the oil supply of pre- 

 Columbian America, and apparently it is a product of Peruvian 

 agriculture. It is very likely a gigantic form of some unknown 

 species perhaps native of Mexico. Its cells should be examined, and 

 their size compared with the cells of other species. Its relation to 

 H. tuberosus, the girasole or Jerusalem artichoke, another Indian 

 food plant, is also a matter of interest. In the latter species 

 Cockerell (1919) has described a number of varieties, in cultivation 

 and possible mutations in the shape of tuber, including 

 multituberculatus, fusifortnis, purpureus and purpurellus. 



