156 OF THE FERNS AND FLOWERING PLANTS 



crown of the root is encircled by round or cordate leave 

 which quickly decay and vanish ; hence the origin of its 

 specific title. 



Here then is a case in point, illustrating the need of gather- 

 ing examples of all the leaves, radical and cauline alike. 



There are certain families also, like the Roses and 

 Brambles, in which the leaves vary much in form according 

 to the part of the plant on which they grow. Specimens of 

 these variations must be gathered, if the student hopes to 

 have at all a satisfactory collection. 



Where the plants are either monoecious or dioecious, it 

 stands to reason that both the sexes must be secured, 

 whether found on separate individuals, or on different 

 parts of the same plant. 



The fructification plays a most important part among 

 both generic and specific characteristics. What, for instance, 

 is the value of a flower, taken alone, among the Cruciferge 

 and Umbelliferae ? Almost nil ! It is to the fruit that we 

 have to look to bring order out of chaos, and settle the 

 limits of genera. In a modified degree the same may be 

 said of other families. 



As many species flower through a large part of the 

 year, there is seldom any difficulty in securing with the 

 flower the half- developed fruit, which should be noted 

 down and again visited at a later period, when the seed- 

 vessel is mature. The Cruciferge, except in their earliest 

 stage, are tolerably certain to supply the collector with both 

 floAversand fruit — the latter in a more or less advanced con- 

 dition — the ripest at the base of the stem, and so passing 

 through every stage up to the barely opened corolla. 



Another group of plants, which has to be carefully 

 watched, are those trees and shrubs in which the flowers 

 are produced on naked branches, the leaves not appearing 

 until some time after the flowers themselves have withered 

 away. Of course, in such instances, Hower and leaf must 

 be gathered on different occasions. Only let the collector 

 be careful to take the latter from the same specimen, from 



