CHAPTER XXIV 



PLANTS ADAPTED TO VARIOUS TYPES OF SOIL 



CONDITIONS 



A VERY important factor in determining the sorts of plants adapted 

 to any specific location is the soil type. By soil type is meant the 

 relative acidity or alkalinity of the soil elements, the relative fineness 

 of the soil particles, and the relative state of dryness of the soil material. 

 All of these conditions overlap and combine with one another and pro- 

 duce soil types which are favourable for certain groups of plants and 

 unfavourable for other groups. The exact physiological reasons why a 

 plant should succeed so much better on one soil type than on another 

 is seldom exactly understood; but practical experience has helped to 

 solve many problems and to bring out many interesting facts. 



Plants adapted to boggy soils are likely to be shallow-rooted like the 

 elm, and they are able to withstand a soil condition which is poorly 

 aerated and almost invariably acid. In fact, a pond full of alkaline or 

 limy water will generally be found practically devoid of plant life, 

 while in an acid pond plants thrive so that they gradually displace 

 the water as in sphagnum bogs, which were open ponds at one time 

 but have lost that character through the excessive growth of plants. 

 In a true bog there is practically no free drainage except during the 

 spring thaw or flood time. 



Plants adapted to bog gardens are called bog plants. Perhaps the 

 most prominent of these perennials are the different varieties of the 

 lady-slipper and the pitcher plant. One of the most essential things 

 for the success of bog garden plants is to have a moist condition which 

 does not vary to any marked degree. It is much better to have the 

 ground surrounding the roots of these plants over-saturated than to 

 have the degree of moisture become too much depleted,' as the water 

 table throughout the entire area of the bog garden should be main- 

 tained at a constant level and at the same time the water should not be 

 allowed to become stagnant. If the area which is being developed as a 

 bog garden does-not naturally possess a growth of certain plants which 

 one knows to be indigenous to bog areas then investigation should be 



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