44 
THE FIRST BOOK OF BOTANY. 
EXERCISE VII. 
The Petiole, Colors, Surface • 
If you have gathered and studied all the leaves 
you could find, as directed in former exercises, when 
now you look at leaves you notice what parts make 
them up, their style of venation, their margins, their 
shapes at their bases and apices; if they are lobed 
leaves, you inspect and count the lobes, and you try 
to say in one word, if possible, what is their general 
shape. 
Put three more questions to this list, and when all 
are answered you have given a botanical description 
of a simple leaf. The first of these new questions is, 
Petiole? Tell whether the petiole is roundish, angu¬ 
lar, furrowed, long or short, straight or crooked, stiff 
or flexible. 
The next question is, Color ? Have you not seen 
that leaves vary in color from dark to light green; 
that they are sometimes spotted, or striped with 
brown, red, and other colors ; that the under side often 
has one color, and the upper another ? This question 
will be easily answered. 
Then you must observe the qualities of the sur¬ 
face of a leaf. If it is not hairy, botanists call it 
glabrous . They have a word also for densely woolly 
surfaces— tomentose. Sometimes the surface is very 
shiny. In answering this question, put down what¬ 
ever appears to be the character of the surface you 
are describing. 
The surfaces of plants are said to be Silky when 
the hairs are long, very fine, and pressed down closely, 
so as to present a silky appearance. 
