THE AMERICAN BOTANIST 73 



plants are about, it sets up its infection directly upon the 

 wheat plant. The barberry, therefore, comes in as a possible 

 harborer of the rust only, not as an essential factor in its distri- 

 bution. The destruction of all barberry bushes would not era- 

 dicate the wheat rust. In view of this fact, one wonders why 

 all this hostility to the barberry. If the shrub happens to 

 grow close to the wheat-fields, the rust may be found upon 

 its leaves, but elsewhere it is so rare that many good botanists 

 and most farmers have never seen it. Surely to insist upon 

 the destruction of the barberry in our parks and large private 

 grounds is carrying the matter too far. Incidentally this re- 

 minds us that the nurserymen have raised a large sum for 

 the purpose of inducing the public to plant more shrubbery. 

 It is likely that they do not feel bad at the barberry's plight. 

 At any rate the war is on and the barberry will have to 

 capitulate. Fortunately the Japanese barberry so extensively 

 used in hedges and other plantings does not harbor the wheat 

 rust. Berberis Canadensis and B. vulgaris are regarded as 

 the sole offenders. People invited to pull up their barberry 

 bushes should make sure that the plants are the suspected 

 species before rooting them out. 



* * * 



The question whether or not, in the absence of better food 

 plants, man could have originated forms just as good from 

 the wild plants in the cooler parts of North America has never 

 been decided ; but the fact is, he has not done so. The tomato, 

 potato, maize, bean and various other vegetables are of Ameri- 

 can origin, but they are all natives of the tropics and their 

 appearance in more temperate regions is due to man's interven- 

 tion. American food plants, however, appear not to have 

 received half the attention they deserve. Of the cultivated 

 plants, maize has been somewhat more extensively differenti- 

 ated than some of the others, for we now have sweet corn and 

 pop corn, as well as the ordinary field corn, and the breeders 



