728 A TEXT-BOOK OF BOTANY. 



Then again, there are plants which grow only in the rich woodland 

 soil, while others grow in barren soil in open places. Some plants 

 require special kinds of soil, as Atropa Belladonna and Cannabis 

 sativa, which do not seem to reach a high state of cultivation except 

 in a calcareous soil. On the other hand, the plants of the Ericaceae 

 are peculiar in that they require an acid soil (pp. 250; 656). 



In beginning this work in a new locality it is very important 

 to make a rather careful survey of the plants growing wild, or 

 those which have become naturalized. It would be safe to say 

 that within certain limits, if there are a number of genera of any 

 family well represented that has some of the habits of the plant 

 with which one desires to experiment with, there is a probability 

 that it may be grown successfully. This can be ascertained to some 

 extent by the nature of the plants that are brought under cultiva- 

 tion. For instance, digitalis might be grown very successfully 

 in localities where it is cultivated and has become naturalized. 

 By a priori reasoning, in the cultivation of licorice, the ideal 

 location for growing the plant would be in the West and North- 

 west where the wild licorice, Glycyrrhiza lepidota, is indigenous. 

 In addition, it is necessary to study the best ways of propagating 

 the plant one wishes to grow. Sometimes this is by means of 

 seeds, as in belladonna and digitalis ; at other times it is by propa- 

 gation of rhizomes, as hydrastis and glycyrrhiza; or again by 

 root-stocks or prostrate stems, as in the mints. Sometimes both 

 seeds and cuttings may be used, as in the case of hydrastis. 



PLANTS GROWN FROM SEEDS. A large number of plants can be 

 grown from seeds, and when they are grown in this manner, espe- 

 cially in a temperate .climate, where the growing season is rather 

 short, it is necessary to begin the germination of the seed early 

 in the spring. This must be done in- the house or under conditions 

 where there is some protection. They may be sown either in small 

 boxes or seed pans, in which the soil is quite sandy OT made up 

 largely of broken granitic rock (Fig. 400), and which must be 

 clean and free from organic matter that is likely to mould. The 

 seeds should not be planted too deep, and the boxes or pans should 

 be covered with glass so as to condense or hold moisture. Of 

 course, where there is the necessary attention, so far as keeping 

 the earth moist is concerned, this can be dispensed with. The 



