THE STEM OF PLANTS. 25 
year, two years, or more, they are called annual, biennial, or 
perennial. Aborescent stems which live a greater or less number 
at 
Fig. 25.—Stipe of the Palm-tree. 
of years, and form solid wood, are “said to be ligneous, or woody. 
The soft stems of annual, biennial, or perennial plants are called 
