FORMS OF THE LEAF-STEMS. 



75 



CHAPTER XVI. 



FORMS OF THE LEAF-STEMS. 



222. The leaf-stems are those forms which, with internodes 

 fully developed, rise into the air crowned with leaves. The 

 principal forms are the caulis, culm, trunk, caudex, and vine. 

 They are either herbaceous or woody. They bear fruit but one 

 season and then perish, at least down to the root, scarcely becom- 

 ing woody ; as seen in Mustard, Radish, and Grasses. But the 

 woody leaf-stems survive the Winter, and become firm and solid 

 in substance in after years ; as do all the forest trees. 



254 



252, Scale-stem (Dicentt 



llariii). 253, A flower of the same. 254, A flower of D. Canadeusta, 

 255, Leaf-stem (Chimaphila maculata). 



223. CAULIS is a term generally applied to the annual leaf- 

 stems of herbaceous plants. " Halm" is a term used in England 

 with the same signification. Caulescent and acaidcscent are con- 



