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 Crucifer® 
and Umbellifer® ? 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 Crucifer®, except in their earliest 
stage, are tolerably certain to supply the collector with both 
flowers and 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, flower and leaf must 
be gathered on different occasions. Only let the collector 
be careful to take the latter from the same specimen, fiom 
