CHAPTER XXVIII 



WHERE PLANTS GROW 



354. Environment. — The circumstances and surround- 

 ings in which an organism lives constitute its environment. 

 The environment comprises effects of soil, moisture, tempera- 

 ture, altitude, sunlight, competition with animals and other 

 plants, and the like. An organism is greatly influenced by 

 the environment or conditions in which it lives. Not only 

 must a plant live and grow and multiply its kind, but it 

 must be capable of withstanding diverse environments. 



355. The particular place in which a plant grows is known 

 as its habitat (i.e., its "habitation"). The habitat of a given 

 plant may be a swamp, hill, rock, sand plain, forest, shore. 

 The plant inhabitants of any region are known collectively 

 as its flora. Thus we speak of the flora of a meadow or a 

 hill or a swamp, or of a country. The word is also used 

 for a book describing the plants of a region (as in Part IV). 



356. Plants Grow Where They Must.— The plant is not 

 able to choose its environment. It has no volition. Its seeds 

 are scattered, and only a few of them fall in favorable places. 

 The seeds make an effort to grow even though the places are 

 not favorable ; and so it happens that plants are often found 

 in places that are little adapted to them. See the fern 

 growing on a brick in Fig. 74. Plants must grow in 

 unoccupied places. 



357. Not only do the seeds fall in unfavorable places, 

 but most places are already occupied. So it comes that 

 plants grow where they must, not always where the conditions 

 are the most favorable. There are, of course, certain limits 

 beyond which plants cannot grow. Water-lilies can thrive 



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