LECT. VI.] THE STEM. CLASSIFICATION. 279 



Algae, and the Ferns ; and is itself supported on a 

 species of real stem (which I shall soon have occa- 

 sion to describe to you), the stipe*, neither of them 

 can with propriety be classed with stems. Mirbel-f- 

 and Mr. Keith J omit the flower-stalk in their enu- 

 meration of the species of the stem, and certainly 

 with some propriety ; for, although it closely re- 

 sembles the stem in its structure, yet, in an ele- 

 mentary work, it is undoubtedly more intelligible 

 to the student to describe it as a part only of it 

 bearing the fructification, except when it proceeds 

 immediately from the root. Contemplating the 

 subject nearly in a similar point of view, I think 

 we are authorized in distributing stems into Jive 

 distinct species : the trunk, the stalk, t\\Q straw, 

 the scape, and the stipe. 



1. TRUNK (Truncus) is the appellation given 

 to the stems of trees and shrubs . The trunk is 



* " Frons est dilatatio vegetabilis herbacea quae arete 

 " cum cormi specie, qua sustentatur cohaeret, Palmis, Filici- 

 " bus, Algisque propria." Willdenou, Spec. Plant, tomus 

 v. Introd. p. xxi. 



f Siemens de Phys. vg. p. 99 and 622. 



J System of physiological Botany, vol. i. p. 43. 



Linnaeus uses the term trunk in the generic sense in which 

 I have used the word stem ; and thus defines it : " TRUNCUS 

 " folia et fructificationem profert ; species ejus sunt vii. Caidis, 

 " Gulmus, Scapus, Pedunculus, Petiolus, Frans, Stipes; at 

 " ttamus pars est." Phil. Bot. 82. 



T 4 



