50 NOMENCLATURE. 



the past year annotini ,• aiul tlioso of the year before the 

 hist himi. 



63. 



When a plant springs up, and grows durhig the first year, 

 and during the second puts on fruit and dies, it is called a 

 biennial {biennis)^ the sign for which is i . 



If a plant lasts several years, and every year sends out 

 new matter from its root, it is called perennial (perennis), the 

 sign of which is "U. 



CHAP. III. 



NAMES OF THE ORGANS. 



L The Root 



64. 



The root (radix), is that part of the plant by which it 

 descends into the earth. It may be considered as a part of 

 the stem, which has been changed only by the covering of 

 earth. 



But the root is distinguished from the radicle, or fibrils 

 of the root {radicula. fibrillar), which are branches, or fibres, 

 that descend from the principal root. 



65, 



A thickened root, in which we can commonly distinguish 

 the solid kernel from the softer surrounding matter, is called 

 a tuber (tuber) , (288.) The forms of these are so extremely 

 various, that they pass from the common spindle-form to the 

 perfectly spherical, the turbinated, and other forms ; (Tab. 

 VI. Fig. 1. 3.) 



