78 



ACADEMIC BOTANY. 



LESSON XV. 



UPPER (SUPERTEKKANEAN) STEM. 



155, 156. Stem growth and names. 157. Herbs. 158. Shrubs and 

 Trees. 159. Descriptive terms. 160. Climatic changes. 161. Age. 

 162. Monocarpic Plants. 163. Tree Forms. 164. Stem Habits. 165. 

 Lianes, Lianas. 166. The term Vine. 167. Triangular and Square 

 Stems. 168. Fleshy Stems. 169. Branches. 170. Transformations. 

 171. Spines, Thorns, Tendrils. 172. Prickles and Hairs. 



155. Stems, as to manner of growth, are, as we know, 

 Simple in Aorogens and Endogens, — Tree-Fern, Grass-tree 



\W/\[m , I /^ -^^tt.'^--^^-i=ism: -. Excurrent in 



Gymnosperms, — 

 Pines (Fig. 97); 

 Solvent in Exo- 

 gens, — Plane- 

 tree (Fig. 98). 



They are named as 

 follows : 



Caudex, the stem 

 of Ferns (Acrogens) ; 



Oidm, the stem of 

 Grasses (Endogens) ; 



Stipe, the stem of 

 Palms (Endogens) ; 



Stem, the general 

 name of herbaceous 

 and woody climbers, 

 bushes, and shrubs ; 



Trunk, the body 

 of trees in Gymno- 

 sperms and Bxogens, but applied also to Endogens and Aerogens. 



156. Plants as to age, texture, and form are classed as 

 Herbs, Shrubs, Trees. 



157. Herbs (except the grasses) have soft stems. They 

 include 



Annuals, that sprout, bloom, bear fruit, and die within 



Flu. 96. — GrasB-tree, Black Boy {jratdlifm-lKza haatUis), of 

 Australia ; 8t. 6 to 10 ft. high. 



