EXPLANATORY 
To he carefully studied before using the charts 
The characteristics chosen for the charts are in general 
whether the plant is a shrub or an herb, its stem, the grouping 
and shape of its leaves, the grouping and shape of the flowers. 
With these features, therefore, one should be more or less famil- 
iar; thus, he should know the following facts: 
A shrub is a woody plant smaller than a tree. 
An herb is a plant with a soft stem dying down every year. 
It may generally be assumed in this book that a plant is an 
herb unless it is definitely stated that it is a shrub. 
One must learn to observe not only the flowers but also the 
plants that bear them, not alone for the general interest, but 
because it is often a necessary step in the identification of the 
flower. Thus, one fundamental difference between plants is in 
the way their leaves are arranged, whether opposite, whorled, 
alternate, or from the root only. It is also important to dis- 
tinguish the simple from the compound leaf. 
With regard to the flowers themselves, one must note whether 
they grow separately or in groups, and if the latter, the form 
of the group. The shape of the flower must, of course, be noted, 
and whether all the parts of a complete flower are present, 
namely, calyx, corolla, stamens, and pistil. 
It is also desirable to gain at least a nodding acquaintance 
with the prominent flower families. 
These subjects are elaborated in the following pages. 
