20 BOTANY FOR BEGINNERS CHAP. 



Shrubby Stems differ from those named above in being 

 hard and woody. They are larger than herbaceous stems ; but 

 smaller than the stems of trees. A shrub is a dwarf tree with 

 a number of permanent woody stems, which divide from the 

 bottom. A shrub differs from a tree (a) in the stems being 

 more slender, and (b) in not growing more than twenty feet high. 

 The following are typical shrubs : Box, Heath, Rose, Rhodo- 

 dendron, Gooseberry and Currant. 



HERBACEOUS. SHRUBBYwWOOW STEMS. 



FIG. 14. Diagram illustrating herbaceous, shrubby, and woody stems. 

 A = Herbaceous. B = Shrubby. C = Woody. S = Section. 



Woody Stems are large, and last for a number of years ; 

 they shoV rings of growth if cut across. Our forest trees such 

 I^LS the Oak, Beech, Fir, Lime, and Ash have woody stems. 

 * Aerial Stems grow above the ground, as those of the Oak, 

 Wallflower, and Foxglove. Several forms of aerial stems are 

 distinguished : 



The Runner is a stem which creeps along the surface of the 

 ground, and produces adventitious roots from its underside, and 

 leaves from its upper surface, e.g., the Strawberry (Fig. 15). 



The Off-set is a stem which is produced from the parent stem ; 

 it creeps along for a short distance and then takes root, e.g., the 

 House-leek (Fig. 16). 



The Stolon is a branch which takes root at its end, thus pro- 

 ducing a new plant, e.g.) Couch-grass (Fig. 17), Gooseberry, and 

 Currant. 



