CHAPTER III— STEMS 

 I. STEMS AS ORGANS OF DISPLAY 



General remarks on stems. — Stems are concerned chiefly with 

 reproduction and with the display of other organs, horizontal stems 

 taking the chief part in the former and erect stems in the latter. 

 Though making up the greater part of the stem, the conductive and 



Fig. 951. — Palmetto trees {Sabal Palmetto), illustrating the tree rosette habit and 

 the absence of branching; note the persistent leaf bases which form a protective stem 

 covering; Ocala, Fla. — Photograph by E. W. Cowles. 



mechanical tissues may be regarded as structures incident to the display 

 of leaves and reprodujctive organs, since they give these organs water and 

 mechanical support. Usually the character of the stem determines the 

 form of the plant body, as is indicated by the old and obvious classifica- 

 tion of plants into trees, shrubs, and herbs. A tree possesses a tall, 



64s 



