22 Bulletin of the University of Texas 
ous.’’ The determination is then checked by turning to the de- 
scription of the species and consulting the illustration. If the 
pine is taken, the first choice goes to ‘‘leaves needle scale or awl- 
IV. Lobed Simple Leaves. 
Bi 
Se 
Pinnately: 1. -—Lobed. 3. Cleft. 5. Parted. -7. Divided. 
Paimately: 2. -tobed= 42 Clert: . Parted. 8. Divided. 

shaped,’’ etce., which leads to the family Pinaceae. Here the 
decision is between *‘leaves all needle-shaped’’ and ‘‘leaves seale- 
lke and appressed to the stem, or some of them awl-shaped, 
spreading.’’ If the leaves are needle-shaped and borne in elus- 
ters of two to five, the species goes to the genus Pinus. 
It is believed that practice in the use of the key will soon 
enable one to locate the family, genus, and species with almost 
certain accuracy. It must be borne in mind that accuracy of 
observation is necessary to its successful use. 
