438 Injiuence of Climale on Vegetation. 



for growing those plants most commonly found in our stoves 

 and green-houses. 



Many of our most beautiful exotic plants come from be- 

 tween the tropics : to know how to manage them advantage- 

 ously, we must, therefore, consider what is the usual climate 

 of their native region. These plants may be divided into 

 seven classes, according to their habitats ; and we take their 

 native climates in succession. 



The first class are those plants which grow in the open 

 plains, exposed to bright sunshine, and enjoying abundance 

 of air. Here there are two essentials, without which tropical 

 plants of this description cannot be expected to thrive ; viz., 

 light and air : the latter being, of course, warm, to imitate 

 that of their native plains. These countries are subject to 

 long seasons of drought, followed by heavy rains, lasting for 

 several months. The plants have, consequently, two distinct 

 periods : one of growth, during which they require heat and 

 abundant moisture; and one of repose, during which they 

 also want excessive heat, but accompanied by complete 

 drought. Very few gardeners ever think of this : even the 

 more scientific are generally satisfied with learning the degree 

 of heat which the plants can bear in their native regions ; but 

 the accompanying circumstances are rarely, if ever, taken into 

 consideration. It is so difficult to imagine circumstances 

 totally different from those by which^we have been always 

 surrounded, that very few gardeners can be persuaded to give 

 their plants no water for several weeks or months, and to in- 

 undate them at another season : yet, without this treatment, 

 the plants must be in an unnatural state, and cannot be 

 expected to thrive. Another important mistake is, keeping 

 the stove at the same temperature during the night as during 

 the day. Gardeners often appear to think that they have not 

 done their duty by their plants unless they have made them 

 quite as warm and comfortable for the night as, perchance, 

 they would like to be themselves. Nothing can be more con- 

 trary to nature than this practice ; as, in most hot countries, 

 the nights are comparatively cold. 



Plants from the woody districts between the tropics require 

 very different management from those which grow in the 

 plains. Many of the orchideous plants, and the exotic ferns, 

 grow in shady places, sheltered from every blast of wind, and 

 flourish in an atmosphere almost stifling from its warmth and 

 moisture. These plants, if exposed, to the same treatment as 

 those from open plains requiring the same degree of heat, 

 would inevitably die, as air and bright light would destroy 

 them. In their native country, the epiphytes grow on the 



