THE BOTANICAL HISTORY OF THE CULTIVATED VIGNAS. 9 



weight. It is an interesting fact that several varieties here referred 

 to V. unguiculata that have become naturalized in the South have 

 unusually small seeds. It is quite possible that V. catjang and V. 

 unguiculata are merely varieties of a single species, the small-seeded 

 varieties only tending to persist when growing wild or constantly 

 subject to weevil attack. It is undoubtedly a fact that the forms 

 with small and hard seeds are less injured by weevils than those 

 with larger and softer seeds. It may, indeed, be true that this one 

 factor tends constantly to eliminate the large- seeded forms when 

 growing wild so that only the small-seeded ones persist. 



Of the three species the cowpea is by far the most important, and 

 excepting where specially indicated the following pages particularly 

 refer to this species. Where all three species are considered collec- 

 tively they are spoken of as " vignas." 



THE BOTANICAL HISTORY OF THE CULTIVATED VIGNAS. 



In view of the very numerous varieties of cowpeas, catjangs, and 

 asparagus beans, it is not at all surprising that descriptive botanists 

 have confused them greatly. It must be borne in mind that the 

 older botanists had as material for investigation only one, or, at 

 any rate, only a few forms, and were, therefore, unable to judge 

 properly of the weight to be given to each character. The earliest 

 history of the cowpea has been very fully given by Wight. 1 The 

 following data regarding the purely botanical history of the three 

 agricultural species present the conclusions arrived at from the 

 study of the large amount of material we have grown. 



ASPARAGUS BEAN. 



The asparagus bean was first described by Linnaeus, in 1763, under 

 the name of Dolichos sesquipedalis. His material came from 

 America, though the plant is undoubtedly native to southern Asia. 

 There could seem to be no question regarding the identity of this 

 species, and no other specific name has ever been given to it. Its 

 proper botanical name is Vigna sesquipedalis (L.) W. F. Wight. 

 Martens (Die Gartenbohne, ed. 2, 1869, p. 100) makes the error of 

 identifying it with Dolichos sinensis Stickman, which name unques- 

 tionably applies to the cowpea. He further quotes Dolichos ses- 

 quipedalis as a synonym. This species does not seem to have been 

 figured by any pre-Linnsean authors, but a handsome colored plate 

 is given by Jacquin. (Hortus Botanicus Vindobonensis, 1770, vol. 1, 

 pi. 67.) 



1 Wight, W. F. Bulletin 102, pt. 6, Bureau of Plant Industry, U. S. Dept. of Agri- 

 culture, 1907. 

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