RECOGNITION OF THE CHARACTER OF SOILS. 



517 



some cases no amount of trimming will result in the formation 

 of anything more than bushes. 



It may be objected that the arid climate as such, and not the 

 calcareous nature of the soil, is the cause of this tendency. It 

 is unquestionable that this low-branching habit is a distinct 

 advantage to the plants, whose trunks would otherwise be fre- 

 quently scorched by the hot summer sun ; as happens when 

 Eastern settlers try to grow " standard " fruit trees, with the 

 result that a " sore," or sunburnt streak is formed on the south- 

 west side of the exposed trunk. All orchard trees should 

 therefore be pruned " vase-shape " in arid climates, partly for 

 this, partly for other reasons. But this cannot explain the 

 fact that seedlings from eastern acorns act precisely as do accli- 

 mated trees ; so that it is not a case of the survival of the 

 fittest to endure arid conditions. 



Tall Growths of Conifers. Moreover, while the rule holds 

 good with almost all deciduous trees, it is not applicable to the 

 Conifers; which in the case of the Sequoias (redwoods and 

 "big-trees"), sugar pine and others, exemplify some of the 

 tallest growths known in the world. The Eastern Cedar or 

 Juniper grows tall only on sufficiently calcareous soils, and in 

 the Mississippi Valley states at least, wherever it occurs is an 

 unfailing indication of calcareous lands. The extended oc- 

 currence of the spruce on the Allegheny Ranges, where lime- 

 stone formations prevail so largely, seems to indicate a similar 

 preference for calcareous lands. And this is certainly true of 

 the black locust, which reaches its extreme southern range in 

 the cretaceous hills of Northeastern Mississippi, showing the 

 stout, stocky form it also assumes when planted in the calcare- 

 ous black-prairie lands of Illinois. 



Herbaceous Plants as Soil Indicators. While herbaceous 

 plants are not as generally considered by land-seekers in judg- 

 ing of soil fertility and character, it goes without saying that 

 very many are quite as characteristic as the tree vegetation, 

 especially when deep-rooting, so as not to indicate merely the 

 character of a few inches of surface soil. 



In the Middle West of the United States especially, a large 

 number of the Composite serve as marks of high productive 

 capacity. This is particularly true of the larger species of 

 the sunflower tribe, among which Helianthus grosse-serratus 



