20 OfilGIN OF CULTIVATED PLANTS. 



few varieties of fruit trees which the Komans did not 

 possess, and some ornamental plants, were, however, then 

 brought to Europe. 



The discovery of America in 1492 was the last great 

 event which caused the diffusion of cultivated plants 

 into all countries. The American species, such as the 

 potato, maize, the prickly pear, tobacco, etc., were first 

 imported into Europe and Asia. Then a number of 

 species from the old world were introduced into America. 

 The voyage of Magellan (1520-1521) was the first direct 

 communication between South America and Asia. ^ In the 

 " same century the slave trade multiplied communications 

 between Africa and America. Lastly, the discovery of 

 the Pacific Islands in the eighteenth century, and _ the 

 growing facility of the means of communication, combined 

 with a general idea of improvement, produced that more 

 general dispersion of useful plants of which we are 

 witnesses at the present day. 

 ^ 5. Philology. The common names of cultivated plants 

 are usually well known, and may afford indications touch- 

 ing the history of a species, but there are examples 

 in which they are absui'd, based upon errors, or vague 

 and doubtful, and this involves a certain caution in 

 their use. 



I could quote a number of such names in all languages; 

 ib is enough to mention, in French, hl4 de Turquie, maize, 

 a plant which is not a wheat, and which comes from 

 America; in English, Jerusalem artichoke (Helianthus 

 tuberosus), which does not come from Jerusalem, but 

 from North America, and is no artichoke. 



A number of names given to foreign plants by 

 Europeans when they are settled in the ^colonies, ex- 

 press false or insignificant analogies. For instance, the 

 A''ew Zealand flax resembles the true flax \ as little as 

 possible ; it is merely that a textile substance is obtained 

 fiom its leaves. The mahogany apple (cashew) of the 

 French West India Isles is not an apple, nor even the 

 fruit of a pomaceous tree, and has nothing to do with 

 mahogany. 



Sometimes the common names have changed, in 



