GENERAL CHARACTERS OF PLANTS 5 



developed that they are as conspicuous as the ordinary foHage leaves, 

 and in such instances they perform the functions of the latter. 



1 2 



ARRAXGEMENT OP LEA^TIS 

 1. Opposite. 2. Alternate. 3. Whorled. 



The presence and character of the stipules should always be noted. 

 A leaf without stipules is said to be exstipulcite. 



A leaf usually consists of two distinct parts — the petiole or stalk, 

 and the lamina or blade. Some, however, have no petiole, but the 

 blade is in direct contact with the stem. These 

 leaves are said to be sessile, and some of them 

 clasp the stem, or even extend downwards on 

 the stem, forming a wing or a sheath. 



A leaf is said to be simple when the blade 

 is in one continuous whole, even though it may 

 be very deeply divided ; but when the blade is 

 cut into distinct parts by incisions that extend 

 quite into the midrib (the continuation of the 

 stalk to the tip of the leaf), the leaf is compound. 



The student must be careful to distinguish 

 between compound leaves and little branches 

 or tmgs bearing several simple leaves, for they 

 are often very similar in general appearance. 

 The compound leaf may always be known by 

 the total absence of buds, and often by the 

 presence of one or more stipules at the 

 base of its stalk ; while a branch bearing 

 a similar appearance usually has a terminal 

 bud, also buds in the exils of its leaves, 

 and never any stipules at the point where it originates. The 

 distinct parts of compound leaves are termed leaflets. 



LEAF OP THE PANSY 

 WITH TWO LARGE 

 STIPULES. 



