EFFECT OF CLIMATE. 



67 



CLIMATE. 



In reading accounts of agricultural and horticultural experiments and results 

 as detailed in European works, no man of common sense needs to be reminded 

 that difference of climate should always be kept in view ; but the necessity of do- 

 ing this does not justify a stupid rejection of all such works. 



We have repeatedly adverted to this difference of climate, in the way of 

 caution to our readers. On the general subject, we take the following from 

 Johnson's Gardener^s Dictionary : 



Climate controls the growth of plants most 

 imperatively, and in the culliviition of his 

 finiits, flowers, and culinary vegetables, it 

 forms the first object of the gardener's in- 

 quiry. He must know the climate in which 

 any given plant is native ; and secondly, the 

 soil which it affects, before he can cultivate 

 it successfully. How all-influential is climate 

 appears from the fact that dift'erent countries 

 have often a totally different Flora on soils 

 similar in constitution. Thus, as is observed 

 by De Candolle and Sprengel, in The Philo- 

 sophy of Plants, " there are a great many 

 perfect plants which exclusively belong to 

 the Tropics, which never pass beyond them, 

 and which are found equally in Asia and Af- 

 rica, in America and the South Sea Islands, 

 and even in New-Holland. Although, as we 



America, because they are scarcely ten de- 

 grees of longitude from the coast of Portugal. 

 Sicily, and still more, Malta, possess a Flora 

 made up of those of the South of Europe and 

 the North of Africa. The Aleutian Islands 

 share their Flora with the North-west coast 

 of America, and the North-east of Asia, But 

 the most distant countrit's, lying under the 

 same latitude, may have the same or a simi- 

 lar vegetation, while countries or islands 

 which lie between them have not the least 

 share in this particular Flora. The Island of 

 St. Helena, which is scarcely eighteen de- 

 grees of longitude fi-om the West of Africa, 

 and which lies a little farther South than 

 Congo, has yet no plants which are found in 

 those last-named regions. (Roxburgh's List 

 of Plants seen in the Island of St. Helena, 



have said, these are rather families, as Palmae I appended to Beatson's "Island of St. Helena.") 

 Scitamineffi, Museac, Sapindea?, and Anoneae; | .laj.'an has a gi-eal many plants common to 

 or genera, as Epidendrum, Santalum. Olax, | Southern Europe, which however, are not 

 Cymbidium, &c. : yet there are particular | foimd in those regions of Asia that lie under 

 species, which gi'ow in all pai'ts of the world i the same latitude 



only between the tropics, as for instance, He- 

 liotropium Indicum, Ageratum conyzoides, 

 PistiiE 8U-atiotes, Scoparia dulcis, Guilandina 

 Bonduc. SphenocleiE zeylanica, Abrus pre- 

 catorius, Boerhavia mutabilis, &c. But most 

 commonly there are other species, which, un- 

 der the same degree of latitude, supply in the 

 New World the place of related species in the 

 old. Dryas octopetala, indeed, grows equal- 

 ly upon the mountains of Canada, and in Eu- 

 rope ; but Dryas tenella of Pursh, which is 

 very like the former, grows only in Green- 

 land and Labrador, Instead of the Platanus 

 Orientalis, there grows in North America the 

 Platanus Occidentalis; instead of Piiius Cem- 

 bra, in Europe and Asia, there grows in North 

 America Pinus Strobus ; instead of Prunus 

 Laurocerasus, in Asia Minor there grows un- 

 der the same latitude in North America the 

 Pruiius Caroliniana. There are many excep- 

 tions to this rule, however, dej)ending on cir- 

 cumstances that have been already noticed. 

 In the first pl;ice, countries are wont to share 

 thi'ir Floras with neighboring regions, espe- 

 cially islands lying under the same latitixde, 

 as the Azores possess the Floras of Europe 

 and of Northern Africa, rather than those of 

 (163) 



We must farther remark that the eastern 

 countries of the Old World, and the easterrj 

 shores of America, as far as the Allegany 

 Mountains, have a much lower temperature 

 than the western regions ; and that it is al- 

 ways colder in Siberia and the North-east of 

 Asia, than under the same latitude in Eu- 

 rope ; and, that even Petersburg is colder 

 than Upsal, and Upsal than Chnstiauia ; al- 

 though they all three lie in the sixtieth degree 

 of north latitude. In North America the differ- 

 ence is still gi'eater, and there commonly fif- 

 teen degrees of Fahrenheit's thennom(;ter be- 

 tween the temperature of the east and v^'est 

 coast. It hence happened that many plants 

 which in Norway grow under the polar circle, 

 scarcely reach the sixtieth degree on the lim- 

 its between Asia and Europ(\ To this class be- 

 long the Silver Fir, .Mountain Ash, Trembling 

 Po[)lar,Black Alder, and .rimiper. Even in the 

 temperate zone, the vegetation of many trees 

 ceases sooner in the East than in the West. 

 In Lithuania and Prussia, under the fifty- 

 third degree, neither vines nor peaches nor 

 apricots thrive: at least their fruit does no 

 ripen, as also liappens in the middle of Eng- 

 land. The most remarkable example of this 



